1
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Mehta N, Martin JML. On the sensitivity of computed partial charges toward basis set and (exchange-)correlation treatment. J Comput Chem 2024; 45:1017-1032. [PMID: 38216516 DOI: 10.1002/jcc.27294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 12/05/2023] [Accepted: 12/10/2023] [Indexed: 01/14/2024]
Abstract
Partial charges are a central concept in general chemistry and chemical biology, yet dozens of different computational definitions exist. In prior work [Cho et al., ChemPhysChem 21, 688-696 (2020)], we showed that these can be reduced to at most three 'principal components of ionicity'. The present study addressed the dependence of computed partial charges q on 1-particle basis set and (for WFT methods) n -particle correlation treatment or (for DFT methods) exchange-correlation functional, for several representative partial charge definitions such as QTAIM, Hirshfeld, Hirshfeld-I, HLY (electrostatic), NPA, and GAPT. Our findings show that semi-empirical double hybrids can closely approach the CCSD(T) 'gold standard' for this property. In fact, owing to an error compensation in MP2, CCSD partial charges are further away from CCSD(T) than is MP2. The nonlocal correlation is important, especially when there is a substantial amount of nonlocal exchange. Employing range separation proves to be "mostly" not advantageous, while global hybrids perform optimally for 20%-30% Hartree-Fock exchange across all charge types. Basis set convergence analysis shows that an augmented triple-zeta heavy-aug-cc-pV(T+d)Z basis set or a partially augmented jun-cc-pV(T+d)Z basis set is sufficient for Hirshfeld, Hirshfeld-I, HLY, and GAPT charges. In contrast, QTAIM and NPA display slower basis set convergence. It is noteworthy that for both NPA and QTAIM, HF exhibits markedly slower basis set convergence than the correlation components of MP2 and CCSD. Triples corrections in CCSD(T), denoted as CCSD(T)-CCSD, exhibit even faster basis set convergence.
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Affiliation(s)
- Nisha Mehta
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Reḥovot, Israel
| | - Jan M L Martin
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Reḥovot, Israel
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2
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Irimia M, Wang J. Self-consistent field method for open-shell systems within the density-matrix functional theory. J Comput Chem 2024; 45:222-229. [PMID: 37702200 DOI: 10.1002/jcc.27232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 08/22/2023] [Accepted: 09/05/2023] [Indexed: 09/14/2023]
Abstract
The unrestricted Hartree-Fock method is extended to correlation calculation within the density-matrix functional theory. The method is derived from an entropic cumulant functional for the correlation energy. The eigenvalue equations for the spin-orbitals are modified by the orbital occupation numbers. The Euler equation for the occupation numbers results in the Fermi-Dirac distribution, which is very efficient to update as soon as the orbital eigenvalue equations are solved. The method is demonstrated on the ground state of O2 .
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Affiliation(s)
| | - Jian Wang
- School of Science, Huzhou University, Zhejiang, China
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3
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Bhandary S, Poli E, Teobaldi G, O’Regan DD. Dynamical Screening of Local Spin Moments at Metal-Molecule Interfaces. ACS Nano 2023; 17:5974-5983. [PMID: 36881865 PMCID: PMC10062023 DOI: 10.1021/acsnano.3c00247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 02/23/2023] [Indexed: 06/18/2023]
Abstract
Transition-metal phthalocyanine molecules have attracted considerable interest in the context of spintronics device development due to their amenability to diverse bonding regimes and their intrinsic magnetism. The latter is highly influenced by the quantum fluctuations that arise at the inevitable metal-molecule interface in a device architecture. In this study, we have systematically investigated the dynamical screening effects in phthalocyanine molecules hosting a series of transition-metal ions (Ti, V, Cr, Mn, Fe, Co, and Ni) in contact with the Cu(111) surface. Using comprehensive density functional theory plus Anderson's Impurity Model calculations, we show that the orbital-dependent hybridization and electron correlation together result in strong charge and spin fluctuations. While the instantaneous spin moments of the transition-metal ions are near atomic-like, we find that screening gives rise to considerable lowering or even quenching of these. Our results highlight the importance of quantum fluctuations in metal-contacted molecular devices, which may influence the results obtained from theoretical or experimental probes, depending on their possibly material-dependent characteristic sampling time-scales.
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Affiliation(s)
- Sumanta Bhandary
- School
of Physics and CRANN Institute, Trinity
College Dublin, The University
of Dublin, Dublin 2, Ireland
| | - Emiliano Poli
- Scientific
Computing Department, STFC UKRI, Rutherford
Appleton Laboratory, Didcot OX11 0QX, United Kingdom
| | - Gilberto Teobaldi
- Scientific
Computing Department, STFC UKRI, Rutherford
Appleton Laboratory, Didcot OX11 0QX, United Kingdom
- School
of Chemistry, University of Southampton, Highfield SO17 1BJ, Southampton, United Kingdom
| | - David D. O’Regan
- School
of Physics and CRANN Institute, Trinity
College Dublin, The University
of Dublin, Dublin 2, Ireland
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4
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Gebhardt J, Elsässer C. DFT with corrections for an efficient and accurate description of strong electron correlations in NiO. J Phys Condens Matter 2023; 35:205901. [PMID: 36863031 DOI: 10.1088/1361-648x/acc0be] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 03/02/2023] [Indexed: 06/18/2023]
Abstract
An efficient and accurate description of the electronic structure of a strongly correlated metal-oxide semiconductor like NiO has been notoriously difficult. Here, we study the capabilities and limitations of two frequently employed correction schemes, a DFT+Uon-site correction and a DFT+1/2 self-energy correction. While both methods individually are unable to provide satisfactory results, in combination they provide a very good description of all relevant physical quantities. Since both methods cope with different shortcomings of common density-functional theory (DFT) methods (using local-density or generalized-gradient approximations), their combination is not mutually dependent and remains broadly applicable. The combined approach retains the computational efficiency of DFT calculations while providing significantly improved predictive power.
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Affiliation(s)
- Julian Gebhardt
- Fraunhofer Institute for Mechanics of Materials IWM, Wöhlerstraße 11, 79108 Freiburg, Germany
- Cluster of Excellence livMatS at FIT-Freiburg Center for Interactive Materials and Bioinspired Technologies, University of Freiburg, Georges-Köhler-Allee 105, Freiburg 79110, Germany
| | - Christian Elsässer
- Fraunhofer Institute for Mechanics of Materials IWM, Wöhlerstraße 11, 79108 Freiburg, Germany
- Cluster of Excellence livMatS at FIT-Freiburg Center for Interactive Materials and Bioinspired Technologies, University of Freiburg, Georges-Köhler-Allee 105, Freiburg 79110, Germany
- Freiburg Materials Research Center (FMF), University of Freiburg, Stefan-Meier-Straße 21, Freiburg 79104, Germany
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5
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Watanabe H, Shirakawa T, Seki K, Sakakibara H, Kotani T, Ikeda H, Yunoki S. Monte Carlo study of cuprate superconductors in a four-bandd-pmodel: role of orbital degrees of freedom. J Phys Condens Matter 2023; 35:195601. [PMID: 36866651 DOI: 10.1088/1361-648x/acc0bf] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 03/02/2023] [Indexed: 06/18/2023]
Abstract
Understanding the various competing phases in cuprate superconductors is a long-standing challenging problem. Recent studies have shown that orbital degrees of freedom, both Cuegorbitals and Oporbitals, are a key ingredient for a unified understanding of cuprate superconductors, including the material dependence. Here we investigate a four-bandd-pmodel derived from the first-principles calculations with the variational Monte Carlo method, which allows us to elucidate competing phases on an equal footing. The obtained results can consistently explain the doping dependence of superconductivity, antiferromagnetic and stripe phases, phase separation in the underdoped region, and also novel magnetism in the heavily-overdoped region. The presence ofporbitals is critical to the charge-stripe features, which induce two types of stripe phases withs)-wave andd-wave bond stripe. On the other hand, the presence ofdz2orbital is indispensable to material dependence of the superconducting transition temperature (Tc), and enhances local magnetic moment as a source of novel magnetism in the heavily-overdoped region as well. These findings beyond one-band description could provide a major step toward a full explanation of unconventional normal state and highTcin cuprate supercondutors.
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Affiliation(s)
- Hiroshi Watanabe
- Research Organization of Science and Technology, Ritsumeikan University, Shiga 525-8577, Japan
| | - Tomonori Shirakawa
- Computational Materials Science Research Team, RIKEN Center for Computational Science (R-CCS), Hyogo 650-0047, Japan
- Quantum Computational Science Research Team, RIKEN Center for Quantum Computing (RQC), Saitama 351-0198, Japan
| | - Kazuhiro Seki
- Quantum Computational Science Research Team, RIKEN Center for Quantum Computing (RQC), Saitama 351-0198, Japan
| | - Hirofumi Sakakibara
- Advanced Mechanical and Electronic System Research Center (AMES), Faculty of Engineering, Tottori University, Tottori 680-8552, Japan
- Center of Spintronics Research Network (CSRN), Graduate School of Engineering Science, Osaka University, Osaka 560-8531, Japan
- Computational Condensed Matter Physics Laboratory, RIKEN Cluster for Pioneering Research (CPR), Saitama 351-0198, Japan
| | - Takao Kotani
- Advanced Mechanical and Electronic System Research Center (AMES), Faculty of Engineering, Tottori University, Tottori 680-8552, Japan
- Center of Spintronics Research Network (CSRN), Graduate School of Engineering Science, Osaka University, Osaka 560-8531, Japan
| | - Hiroaki Ikeda
- Department of Physics, Ritsumeikan University, Shiga 525-8577, Japan
| | - Seiji Yunoki
- Computational Materials Science Research Team, RIKEN Center for Computational Science (R-CCS), Hyogo 650-0047, Japan
- Quantum Computational Science Research Team, RIKEN Center for Quantum Computing (RQC), Saitama 351-0198, Japan
- Computational Condensed Matter Physics Laboratory, RIKEN Cluster for Pioneering Research (CPR), Saitama 351-0198, Japan
- Computational Quantum Matter Research Team, RIKEN Center for Emergent Matter Science (CEMS), Saitama 351-0198, Japan
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6
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Lu JB, Jiang XL, Wang JQ, Hu HS, Schwarz WHE, Li J. On the highest oxidation states of the actinoids in AnO 4 molecules (An = Ac - Cm): A DMRG-CASSCF study. J Comput Chem 2023; 44:190-198. [PMID: 35420170 DOI: 10.1002/jcc.26856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 03/18/2022] [Accepted: 03/23/2022] [Indexed: 12/31/2022]
Abstract
Actinoid tetroxide molecules AnO4 (An = Ac - Cm) are investigated with the ab initio density matrix renormalization group (DMRG) approach. Natural orbital shapes are used to read out the oxidation state (OS) of the f-elements, and the atomic orbital energies and radii are used to explain the trends. The highest OSs reveal a "volcano"-type variation: For An = Ac - Np, the OSs are equal to the number of available valence electrons, that is, AcIII , ThIV , PaV , UVI , and NpVII . Starting with plutonium as the turning point, the highest OSs in the most stable AnO4 isomers then decrease as PuV , AmV , and CmIII , indicating that the 5f-electrons are hard to be fully oxidized off from Pu onward. The variations are related to the actinoid contraction and to the 5f-covalency characteristics. Combined with previous work on OSs, we review their general trends throughout the periodic table, providing fundamental understanding of OS-relevant phenomena.
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Affiliation(s)
- Jun-Bo Lu
- Departmentof Chemistry, Southern University of Science and Technology, Shenzhen.,Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering, Ministry of Education, Tsinghua University, Beijing
| | - Xue-Lian Jiang
- Departmentof Chemistry, Southern University of Science and Technology, Shenzhen
| | - Jia-Qi Wang
- Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering, Ministry of Education, Tsinghua University, Beijing
| | - Han-Shi Hu
- Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering, Ministry of Education, Tsinghua University, Beijing
| | - W H Eugen Schwarz
- Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering, Ministry of Education, Tsinghua University, Beijing.,Theoretische Chemie, Fachbereich Chemie und Biologie, Universität Siegen, Siegen, Germany
| | - Jun Li
- Departmentof Chemistry, Southern University of Science and Technology, Shenzhen.,Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering, Ministry of Education, Tsinghua University, Beijing
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7
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Coughlin AL, Pan Z, Hong J, Zhang T, Zhan X, Wu W, Xie D, Tong T, Ruch T, Heremans JJ, Bao J, Fertig HA, Wang J, Kim J, Zhu H, Li D, Zhang S. Enhanced Electron Correlation and Significantly Suppressed Thermal Conductivity in Dirac Nodal-Line Metal Nanowires by Chemical Doping. Adv Sci (Weinh) 2023; 10:e2204424. [PMID: 36437041 PMCID: PMC9839858 DOI: 10.1002/advs.202204424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 10/08/2022] [Indexed: 06/16/2023]
Abstract
Enhancing electron correlation in a weakly interacting topological system has great potential to promote correlated topological states of matter with extraordinary quantum properties. Here, the enhancement of electron correlation in a prototypical topological metal, namely iridium dioxide (IrO2 ), via doping with 3d transition metal vanadium is demonstrated. Single-crystalline vanadium-doped IrO2 nanowires are synthesized through chemical vapor deposition where the nanowire yield and morphology are improved by creating rough surfaces on substrates. Vanadium doping leads to a dramatic decrease in Raman intensity without notable peak broadening, signifying the enhancement of electron correlation. The enhanced electron correlation is further evidenced by transport studies where the electrical resistivity is greatly increased and follows an unusual T $\sqrt T $ dependence on the temperature (T). The lattice thermal conductivity is suppressed by an order of magnitude via doping even at room temperature where phonon-impurity scattering becomes less important. Density functional theory calculations suggest that the remarkable reduction of thermal conductivity arises from the complex phonon dispersion and reduced energy gap between phonon branches, which greatly enhances phase space for phonon-phonon Umklapp scattering. This work demonstrates a unique system combining 3d and 5d transition metals in isostructural materials to enrich the system with various types of interactions.
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Affiliation(s)
| | - Zhiliang Pan
- Department of Mechanical EngineeringVanderbilt UniversityNashvilleTN37235USA
| | - Jeonghoon Hong
- Department of PhysicsIncheon National UniversityIncheon22012Korea
| | - Tongxie Zhang
- Department of PhysicsIndiana UniversityBloomingtonIN47405USA
| | - Xun Zhan
- Electron Microscopy CenterIndiana UniversityBloomingtonIN47405USA
| | - Wenqian Wu
- Department of Mechanical and Materials EngineeringUniversity of NebraskaLincolnNE68588USA
| | - Dongyue Xie
- Department of Mechanical and Materials EngineeringUniversity of NebraskaLincolnNE68588USA
- Center for Integrated Nanotechnologies, MPA DivisionLos Alamos National LaboratoryLos Alamos87545United States
| | - Tian Tong
- Department of Electrical and Computer Engineering and Texas Center for Superconductivity (TcSUH)University of HoustonHoustonTX77204USA
| | - Thomas Ruch
- Department of PhysicsIndiana UniversityBloomingtonIN47405USA
| | | | - Jiming Bao
- Department of Electrical and Computer Engineering and Texas Center for Superconductivity (TcSUH)University of HoustonHoustonTX77204USA
| | | | - Jian Wang
- Department of Mechanical and Materials EngineeringUniversity of NebraskaLincolnNE68588USA
| | - Jeongwoo Kim
- Department of PhysicsIncheon National UniversityIncheon22012Korea
| | - Hanyu Zhu
- Department of Materials Science and NanoEngineeringRice UniversityHoustonTX77005USA
| | - Deyu Li
- Department of Mechanical EngineeringVanderbilt UniversityNashvilleTN37235USA
| | - Shixiong Zhang
- Department of PhysicsIndiana UniversityBloomingtonIN47405USA
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8
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Janas DM, Droghetti A, Ponzoni S, Cojocariu I, Jugovac M, Feyer V, Radonjić MM, Rungger I, Chioncel L, Zamborlini G, Cinchetti M. Enhancing Electron Correlation at a 3d Ferromagnetic Surface. Adv Mater 2023; 35:e2205698. [PMID: 36300806 DOI: 10.1002/adma.202205698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 10/07/2022] [Indexed: 06/16/2023]
Abstract
Spin-resolved momentum microscopy and theoretical calculations are combined beyond the one-electron approximation to unveil the spin-dependent electronic structure of the interface formed between iron (Fe) and an ordered oxygen (O) atomic layer, and an adsorbate-induced enhancement of electronic correlations is found. It is demonstrated that this enhancement is responsible for a drastic narrowing of the Fe d-bands close to the Fermi energy (EF ) and a reduction of the exchange splitting, which is not accounted for in the Stoner picture of ferromagnetism. In addition, correlation leads to a significant spin-dependent broadening of the electronic bands at higher binding energies and their merging with satellite features, which are manifestations of a pure many-electron behavior. Overall, adatom adsorption can be used to vary the material parameters of transition metal surfaces to access different intermediate electronic correlated regimes, which will otherwise not be accessible. The results show that the concepts developed to understand the physics and chemistry of adsorbate-metal interfaces, relevant for a variety of research areas, from spintronics to catalysis, need to be reconsidered with many-particle effects being of utmost importance. These may affect chemisorption energy, spin transport, magnetic order, and even play a key role in the emergence of ferromagnetism at interfaces between non-magnetic systems.
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Affiliation(s)
| | - Andrea Droghetti
- School of Physics & CRANN, Trinity College, Dublin, D02 PN40, Ireland
| | - Stefano Ponzoni
- TU Dortmund University, Department of Physics, 44227, Dortmund, Germany
| | - Iulia Cojocariu
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH, 52428, Jülich, Germany
| | - Matteo Jugovac
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH, 52428, Jülich, Germany
| | - Vitaliy Feyer
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH, 52428, Jülich, Germany
| | - Miloš M Radonjić
- Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, Belgrade, 11080, Serbia
| | - Ivan Rungger
- National Physical Laboratory, Teddington, TW11 0LW, UK
| | - Liviu Chioncel
- Theoretical Physics III, Center for Electronic Correlations and Magnetism, Institute of Physics and Augsburg Center for Innovative Technologies, University of Augsburg, 86159, Augsburg, Germany
| | | | - Mirko Cinchetti
- TU Dortmund University, Department of Physics, 44227, Dortmund, Germany
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9
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Moles Quintero S, Haley MM, Kertesz M, Casado J. Polycyclic Hydrocarbons from [4n]Annulenes: Correlation versus Hybridization Forces in the Formation of Diradicaloids. Angew Chem Int Ed Engl 2022; 61:e202209138. [PMID: 35986661 PMCID: PMC9826091 DOI: 10.1002/anie.202209138] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Indexed: 01/11/2023]
Abstract
The conceptual connections between [4n] Hückel antiaromaticity, disjoint orbitals, correlation energy, pro-aromaticity and diradical character for a variety of extended π-conjugated systems, including some salient recent examples of nanographenes and polycyclic aromatic radicals, are provided based on their [4n]annulene peripheries. The realization of such structure-property relationships has led to a beneficial pedagogic exercise establishing design guidelines for diradicaloids. The antiaromatic fingerprint of the [4n]annulene peripheries upon orbital interactions due to internal covalent connectors gives insights into the diradicaloid property of a diversity of π-conjugated molecules that have fascinated chemists recently.
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Affiliation(s)
| | - Michael M. Haley
- Department of Chemistry & Biochemistry and Materials Science InstituteUniversity of OregonEugeneOR 97403-1253USA
| | - Miklos Kertesz
- Department of Chemistry and Institute of Soft MatterGeorgetown UniversityWashingtonDC 20057-1227USA
| | - Juan Casado
- Department of Physical ChemistryUniversity of Málaga29071MálagaSpain
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10
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Tenorio BNC, Ponzi A, Coriani S, Decleva P. Photoionization Observables from Multi-Reference Dyson Orbitals Coupled to B-Spline DFT and TD-DFT Continuum. Molecules 2022; 27:molecules27041203. [PMID: 35208990 PMCID: PMC8879948 DOI: 10.3390/molecules27041203] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 02/02/2022] [Accepted: 02/05/2022] [Indexed: 11/23/2022] Open
Abstract
We present a theoretical model to compute the accurate photoionization dynamical parameters (cross-sections, asymmetry parameters and orbital, or cross-section, ratios) from Dyson orbitals obtained with the multi-state complete active space perturbation theory to the second order (MS-CASPT2) method. Our new implementation of Dyson orbitals in OpenMolcas takes advantage of the full Abelian symmetry point group and has the corrected normalization. The Dyson orbitals are coupled to an accurate description of the electronic continuum obtained with a multicentric B-spline basis at the DFT and TD-DFT levels. Two prototype diatomic molecules, i.e., CS and SiS, have been chosen due to their smallness, which hides important correlation effects. These effects manifest themselves in the appearance of well-characterized isolated satellite bands in the middle of the valence region. The rich satellite structures make CS and SiS the perfect candidates for a computational study based on our highly accurate MS-CASPT2/B-spline TD-DFT protocol.
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Affiliation(s)
- Bruno Nunes Cabral Tenorio
- DTU Chemistry–Department of Chemistry, Technical University of Denmark, Kemitorvet Bldg 207, 2800 Kongens Lyngby, Denmark
- Correspondence: (B.N.C.T.); (S.C.); (P.D.)
| | - Aurora Ponzi
- Department of Physical Chemistry, Ruđer Bošković Institute, 10000 Zagreb, Croatia;
| | - Sonia Coriani
- DTU Chemistry–Department of Chemistry, Technical University of Denmark, Kemitorvet Bldg 207, 2800 Kongens Lyngby, Denmark
- Correspondence: (B.N.C.T.); (S.C.); (P.D.)
| | - Piero Decleva
- Istituto Officina dei Materiali IOM-CNR and Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, 34121 Trieste, Italy
- Correspondence: (B.N.C.T.); (S.C.); (P.D.)
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11
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Abstract
We investigate the Colle-Salvetti (CS) formula, the basis of the Lee, Yang and Parr (LYP) correlation functional used in approximate density functional theory. The CS formula is reparametrized using high-accuracy Hartree-Fock (HF) wavefunctions to determine the accuracy of the formula to calculate anions. Fitting to the hydride ion or the two-electron system just prior to electron detachment at the HF level of theory does not, in general, improve the calculated correlation energies using the parameters derived from the CS/LYP method. An analysis of the CS parameters used in the popular LYP functional demonstrates the ingenuity and perhaps fortuitousness of the original formulation by CS.
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Affiliation(s)
- Adam L. Baskerville
- Department of Chemistry, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QJ, UK
| | - Msugh Targema
- Department of Chemistry, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QJ, UK
| | - Hazel Cox
- Department of Chemistry, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QJ, UK
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12
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Fujimori T, Kobayashi M, Taketsugu T. Energy-based automatic determination of buffer region in the divide-and-conquer second-order Møller-Plesset perturbation theory. J Comput Chem 2021; 42:620-629. [PMID: 33534916 PMCID: PMC7986104 DOI: 10.1002/jcc.26486] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 12/19/2020] [Accepted: 01/15/2021] [Indexed: 11/21/2022]
Abstract
In the linear‐scaling divide‐and‐conquer (DC) electronic structure method, each subsystem is calculated together with the neighboring buffer region, the size of which affects the energy error introduced by the fragmentation in the DC method. The DC self‐consistent field calculation utilizes a scheme to automatically determine the appropriate buffer region that is as compact as possible for reducing the computational time while maintaining acceptable accuracy (J. Comput. Chem. 2018, 39, 909). To extend the automatic determination scheme of the buffer region to the DC second‐order Møller–Plesset perturbation (MP2) calculation, a scheme for estimating the subsystem MP2 correlation energy contribution from each atom in the buffer region is proposed. The estimation is based on the atomic orbital Laplace MP2 formalism. Based on this, an automatic buffer determination scheme for the DC‐MP2 calculation is constructed and its performance for several types of systems is assessed.
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Affiliation(s)
- Toshikazu Fujimori
- Graduate School of Chemical Sciences and EngineeringHokkaido UniversitySapporoJapan
| | - Masato Kobayashi
- Department of Chemistry, Faculty of ScienceHokkaido UniversitySapporoJapan
- WPI‐ICReDDHokkaido UniversitySapporoJapan
- ESICB, Kyoto UniversityKyotoJapan
| | - Tetsuya Taketsugu
- Department of Chemistry, Faculty of ScienceHokkaido UniversitySapporoJapan
- WPI‐ICReDDHokkaido UniversitySapporoJapan
- ESICB, Kyoto UniversityKyotoJapan
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13
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Šulka M, Dubecký M. Fragmentation of natural orbital occupation numbers-based diagnostic of differential multireference character in complexes with hydrogen bonds. J Comput Chem 2021; 42:475-483. [PMID: 33321553 DOI: 10.1002/jcc.26470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 11/24/2020] [Accepted: 12/01/2020] [Indexed: 11/06/2022]
Abstract
We explore the possible route to approximate natural orbital occupation numbers-based diagnostic of differential multireference character of noncovalent energy differences by techniques based on many-body expansion. It turns out that two-body fragmentation of monomers may lead to a reasonable approximation of such a diagnostic in hydrogen-bonded complexes. The results are useful, for example, for assessment of the expected bias cancellation in energy differences of larger systems obtained by single-reference methods.
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Affiliation(s)
- Martin Šulka
- Advanced Technologies Research Institute, Faculty of Materials Science and Technology in Trnava, Slovak University of Technology in Bratislava, Trnava, Slovakia.,Department of Physics, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Matúš Dubecký
- Advanced Technologies Research Institute, Faculty of Materials Science and Technology in Trnava, Slovak University of Technology in Bratislava, Trnava, Slovakia.,Department of Physics, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
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14
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Zheng P, Ji C, Ying F, Su P, Wu W. A Valence-Bond-Based Multiconfigurational Density Functional Theory: The λ-DFVB Method Revisited. Molecules 2021; 26:521. [PMID: 33498268 PMCID: PMC7863953 DOI: 10.3390/molecules26030521] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 01/17/2021] [Accepted: 01/18/2021] [Indexed: 11/29/2022] Open
Abstract
A recently developed valence-bond-based multireference density functional theory, named λ-DFVB, is revisited in this paper. λ-DFVB remedies the double-counting error of electron correlation by decomposing the electron-electron interactions into the wave function term and density functional term with a variable parameter λ. The λ value is defined as a function of the free valence index in our previous scheme, denoted as λ-DFVB(K) in this paper. Here we revisit the λ-DFVB method and present a new scheme based on natural orbital occupation numbers (NOONs) for parameter λ, named λ-DFVB(IS), to simplify the process of λ-DFVB calculation. In λ-DFVB(IS), the parameter λ is defined as a function of NOONs, which are straightforwardly determined from the many-electron wave function of the molecule. Furthermore, λ-DFVB(IS) does not involve further self-consistent field calculation after performing the valence bond self-consistent field (VBSCF) calculation, and thus, the computational effort in λ-DFVB(IS) is approximately the same as the VBSCF method, greatly reduced from λ-DFVB(K). The performance of λ-DFVB(IS) was investigated on a broader range of molecular properties, including equilibrium bond lengths and dissociation energies, atomization energies, atomic excitation energies, and chemical reaction barriers. The computational results show that λ-DFVB(IS) is more robust without losing accuracy and comparable in accuracy to high-level multireference wave function methods, such as CASPT2.
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Affiliation(s)
| | | | | | - Peifeng Su
- Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, The State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China; (P.Z.); (C.J.); (F.Y.)
| | - Wei Wu
- Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, The State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China; (P.Z.); (C.J.); (F.Y.)
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15
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Pérez-Conesa S, Martínez JM, Pappalardo RR, Marcos ES. Combining EXAFS and Computer Simulations to Refine the Structural Description of Actinyls in Water. Molecules 2020; 25:E5250. [PMID: 33187172 PMCID: PMC7697702 DOI: 10.3390/molecules25225250] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/05/2020] [Accepted: 11/08/2020] [Indexed: 11/16/2022] Open
Abstract
EXAFS spectroscopy is one of the most used techniques to solve the structure of actinoid solutions. In this work a systematic analysis of the EXAFS spectra of four actinyl cations, [UO2]2+, [NpO2]2+, [NpO2]+ and [PuO2]2+ has been carried out by comparing experimental results with theoretical spectra. These were obtained by averaging individual contributions from snapshots taken from classical Molecular Dynamics simulations which employed a recently developed [AnO2]2+/+ -H2O force field based on the hydrated ion model using a quantum-mechanical (B3LYP) potential energy surface. Analysis of the complex EXAFS signal shows that both An-Oyl and An-OW single scattering paths as well as multiple scattering ones involving [AnO2]+/2+ molecular cation and first-shell water molecules are mixed up all together to produce a very complex signal. Simulated EXAFS from the B3LYP force field are in reasonable agreement for some of the cases studied, although the k= 6-8 Å-1 region is hard to be reproduced theoretically. Except uranyl, all studied actinyls are open-shell electron configurations, therefore it has been investigated how simulated EXAFS spectra are affected by minute changes of An-O bond distances produced by the inclusion of static and dynamic electron correlation in the quantum mechanical calculations. A [NpO2]+-H2O force field based on a NEVPT2 potential energy surface has been developed. The small structural changes incorporated by the electron correlation on the actinyl aqua ion geometry, typically smaller than 0.07 Å, leads to improve the simulated spectrum with respect to that obtained from the B3LYP force field. For the other open-shell actinyls, [NpO2]2+ and [PuO2]2+, a simplified strategy has been adopted to improve the simulated EXAFS spectrum. It is computed taking as reference structure the NEVPT2 optimized geometry and including the DW factors of their corresponding MD simulations employing the B3LYP force field. A better agreement between the experimental and the simulated EXAFS spectra is found, confirming the a priori guess that the inclusion of dynamic and static correlation refine the structural description of the open-shell actinyl aqua ions.
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Affiliation(s)
| | | | | | - Enrique Sánchez Marcos
- Departamento de Química Física, Universidad de Sevilla, 41012 Sevilla, Spain; (S.P.-C.); (J.M.M.); (R.R.P.)
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16
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Feng Q. First principles investigation of electron correlation and Lifshitz transition within iron polynitrides. J Phys Condens Matter 2020; 33:035603. [PMID: 33078710 DOI: 10.1088/1361-648x/abbb41] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 09/24/2020] [Indexed: 06/11/2023]
Abstract
Metal poly-nitrogen compounds are gaining great interests as potential high energy density materials. Several iron polynitrides have been recently synthesized and investigated under high pressure (2018Nature Communications92756). In this work the electron correlations within these iron poly-nitrogen compounds were self-consistently determined, benchmarked with those obtained from linear response approach. Along with the increase of the concentration of nitrogen, the Coulomb interaction strengths show a monotonic decrease, where FeN and FeN2are antiferromagnetic and the others are ferromagnetic. Then the electron correlation is studied along with the pressure, where the electrons are more delocalized as pressure becomes higher. One electronic topological transition was found for FeN2, owing to a breaking of symmetry of spin and a transition of magnetism induced by a structural change. The band structure, densities of states, Fermi surface and absorption spectra were calculated and discussed.
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Affiliation(s)
- Qingguo Feng
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, Sichuan 610031, People's Republic of China
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17
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Feng Q. Electron correlation effect versus spin-orbit coupling for tungsten and impurities. J Phys Condens Matter 2020; 32:445603. [PMID: 32674082 DOI: 10.1088/1361-648x/aba6a5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 07/16/2020] [Indexed: 06/11/2023]
Abstract
The electron correlation and spin-orbit coupling (SOC) effects are investigated for body-centered-cubic tungsten and intrinsic & irradiative impurities using first principles calculations based upon the density functional theory. It is found that the electron correlation between the localized 5delectrons and the SOC effect are significant in modifying the band structures and the formation energies of defects. For the latter one, the involving of electron correlation always makes the defects stabler than the Perdew-Burke-Ernzerhof results, while the SOC contributes diversely for different defects. Moreover, the migration barrier of single tungsten vacancy moving in ⟨111⟩ direction is explored, where the inclusion of electron correlations remarkably decreases the migration barrier, while the influence of SOC is almost negligible. This study can help to validate the previous studies on irradiative defects in tungsten and improve the further investigations.
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Affiliation(s)
- Qingguo Feng
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, Sichuan 610031, People's Republic of China
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18
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Feng Q. Electronic, magnetic and optical properties of transition-metal and hydroxides doped monolayer g-C 3N 4: a first principles investigation. J Phys Condens Matter 2020; 32:445602. [PMID: 32634793 DOI: 10.1088/1361-648x/aba387] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 07/07/2020] [Indexed: 06/11/2023]
Abstract
The graphitic carbon nitride (g-C3N4) is a promising layered two-dimension material with an opened bandgap. It is of interest to explore the tunability of the bandgap together with the magnetism by doping transition metal atoms. In this work, we investigated the transition metals (Mn, Fe, Co, Ni) and their hydroxides doped g-C3N4monolayers. The electron correlations between the 3delectrons of the doped transition metal atoms are self-consistently calculated and analyzed based on the density functional theory. The magnetism, electronic band structures and optical properties are systematically investigated. It reveals that the transition metal doped g-C3N4is ferromagnetic (FM) state at small doping concentration, where the two spins show different bandgaps. When the doping is high enough, it turns to metallic antiferromagnetic (AFM) state except that Mn doped g-C3N4is metallic FM state. On another hand, the system shows variable absorption spectra at different doping level. When the vacancy sites are fully occupied, a large absorption peak appears around 1.5 eV suitable for visible light. Moreover, within the transition metal hydroxides doped g-C3N4, the global ground state shows as AFM, and the absorption spectra within low energy range is distinct due to the presence of hydroxyl group. Therefore, doping with transition metal atoms and hydroxides can effectively tune the bandgap, magnetism and optical properties of g-C3N4so as to promote its applications.
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Affiliation(s)
- Qingguo Feng
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, Sichuan 610031, People's Republic of China
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19
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Asano K, Sako T, Ishida H. Spin-dependent transient current in transistor-like nanostructures. J Phys Condens Matter 2020; 32:435302. [PMID: 32619998 DOI: 10.1088/1361-648x/aba292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 07/03/2020] [Indexed: 06/11/2023]
Abstract
Transient current in transistor-like nanostructures has been studied by a model of a few electrons confined in a one-dimensional effective potential consisting of three quantum wells, 'source', 'gate', and 'drain'. The time-dependent Schrödinger equation for the electrons has been integrated relying on the symplectic integrator method and the transient current has been calculated as the flux of the probability density of electrons absorbed by the complex absorbing potential placed at the far edge of the drain region. The electrons are initially placed in the source domain as their lowest-energy state for a given spin multiplicity and the source-drain current has been calculated for different gate potential heights. The current for different spin configurations has shown strong emission at different values of the gate potential, suggesting use of the studied nanostructures for extracting current with a specific spin configuration from spin-unpolarized normal current. Dependence of the current emission on electron correlation has also been studied by changing the size of the source domain. The current has shown appreciable differences for different spin configurations for the medium and strong confinement regimes, while these differences become smaller for smaller confinement and tend to diminish in the weak limit of confinement. This observed trend has been rationalized on the basis of the formation of the Wigner lattice states.
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Affiliation(s)
- Katsuya Asano
- Graduate School of Quantum Science and Technology, Nihon University, 1-8-14 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308, Japan
| | - Tokuei Sako
- Graduate School of Quantum Science and Technology, Nihon University, 1-8-14 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308, Japan
- Laboratory of Physics, College of Science and Technology, Nihon University, 7-24-1 Narashinodai, Funabashi, Chiba 274-8501, Japan
| | - Hiroshi Ishida
- College of Humanities and Sciences, Nihon University, 3-25-40 Sakura-Josui, Tokyo 156-8550, Japan
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20
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Onodera M, Kinoshita K, Moriya R, Masubuchi S, Watanabe K, Taniguchi T, Machida T. Cyclotron Resonance Study of Monolayer Graphene under Double Moiré Potentials. Nano Lett 2020; 20:4566-4572. [PMID: 32356662 DOI: 10.1021/acs.nanolett.0c01427] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We report the first cyclotron resonance study of monolayer graphene under double-moiré potentials in which the crystal axis of graphene is nearly aligned to those of both the top and bottom hexagonal boron nitride (h-BN) layers. Under mid-infrared light irradiation, we observe cyclotron resonance absorption with the following unique features: (1) cyclotron resonance magnetic field BCR is entirely different from that of nonaligned monolayer graphene, (2) BCR exhibits strong electron-hole asymmetry, and (3) splitting of BCR is observed for |ν| < 1, with the split maximum at |ν| = 1, resulting in eyeglass-shaped trajectories. These features are well explained by considering the large bandgap induced by the double moiré potentials, the electron-hole asymmetry in the Fermi velocity, and the Fermi-level-dependent enhancement of spin gaps, which suggests a large electron-electron correlation contribution in this system.
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Affiliation(s)
- Momoko Onodera
- Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505, Japan
| | - Kei Kinoshita
- Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505, Japan
| | - Rai Moriya
- Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505, Japan
| | - Satoru Masubuchi
- Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505, Japan
| | - Kenji Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505, Japan
- National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Tomoki Machida
- Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505, Japan
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21
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Alkorta I, Silva AF, Popelier PLA. An Interacting Quantum Atoms (IQA) and Relative Energy Gradient (REG) Study of the Halogen Bond with Explicit Analysis of Electron Correlation. Molecules 2020; 25:E2674. [PMID: 32526931 DOI: 10.3390/molecules25112674] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 06/03/2020] [Accepted: 06/03/2020] [Indexed: 01/18/2023] Open
Abstract
Energy profiles of seven halogen-bonded complexes were analysed with the topological energy partitioning called Interacting Quantum Atoms (IQA) at MP4(SDQ)/6-31+G(2d,2p) level of theory. Explicit interatomic electron correlation energies are included in the analysis. Four complexes combine X2 (X = Cl or F) with HCN or NH3, while the remaining three combine ClF with HCN, NH3 or N2. Each complex was systematically deformed by translating the constituent molecules along its central axis linking X and N, and reoptimising its remaining geometry. The Relative Energy Gradient (REG) method (Theor. Chem. Acc. 2017, 136, 86) then computes which IQA energies most correlate with the total energy during the process of complex formation and further compression beyond the respective equilibrium geometries. It turns out that the covalent energy (i.e., exchange) of the halogen bond, X…N, itself drives the complex formation. When the complexes are compressed from their equilibrium to shorter X…N distance then the intra-atomic energy of N is in charge. When the REG analysis is restricted to electron correlation then the interatomic correlation energy between X and N again drives the complex formation, and the complex compression is best described by the destabilisation of the through-space correlation energy between N and the "outer" halogen.
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22
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Chen J, Mao W, Gao L, Yan F, Yajima T, Chen N, Chen Z, Dong H, Ge B, Zhang P, Cao X, Wilde M, Jiang Y, Terai T, Shi J. Electron-Doping Mottronics in Strongly Correlated Perovskite. Adv Mater 2020; 32:e1905060. [PMID: 31854486 DOI: 10.1002/adma.201905060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 11/21/2019] [Indexed: 06/10/2023]
Abstract
The discovery of hydrogen-induced electron localization and highly insulating states in d-band electron correlated perovskites has opened a new paradigm for exploring novel electronic phases of condensed matters and applications in emerging field-controlled electronic devices (e.g., Mottronics). Although a significant understanding of doping-tuned transport properties of single crystalline correlated materials exists, it has remained unclear how doping-controlled transport properties behave in the presence of planar defects. The discovery of an unexpected high-concentration doping effect in defective regions is reported for correlated nickelates. It enables electronic conductance by tuning the Fermi-level in Mott-Hubbard band and shaping the lower Hubbard band state into a partially filled configuration. Interface engineering and grain boundary designs are performed for Hx SmNiO3 /SrRuO3 heterostructures, and a Mottronic device is achieved. The interfacial aggregation of hydrogen is controlled and quantified to establish its correlation with the electrical transport properties. The chemical bonding between the incorporated hydrogen with defective SmNiO3 is further analyzed by the positron annihilation spectroscopy. The present work unveils new materials physics in correlated materials and suggests novel doping strategies for developing Mottronic and iontronic devices via hydrogen-doping-controlled orbital occupancy in perovskite heterostructures.
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Affiliation(s)
- Jikun Chen
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Wei Mao
- School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan
| | - Lei Gao
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Fengbo Yan
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Takeaki Yajima
- School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan
| | - Nuofu Chen
- School of Renewable Energy, North China Electric Power University, Beijing, 102206, China
| | - Zhizhong Chen
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Hongliang Dong
- Center for High Pressure Science and Technology Advanced Research, Shanghai, 201203, China
| | - Binghui Ge
- Institute of Physical Science and Information Technology, Anhui University, Heifei, 230601, Anhui, China
| | - Peng Zhang
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Xingzhong Cao
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Markus Wilde
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan
| | - Yong Jiang
- Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Takayuki Terai
- School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan
| | - Jian Shi
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
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Vincent MA, Silva AF, Popelier PLA. Atomic Partitioning of the MPn (n = 2, 3, 4) Dynamic Electron Correlation Energy by the Interacting Quantum Atoms Method: A Fast and Accurate Electrostatic Potential Integral Approach. J Comput Chem 2019; 40:2793-2800. [PMID: 31373709 PMCID: PMC6900022 DOI: 10.1002/jcc.26037] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Revised: 07/10/2019] [Accepted: 07/11/2019] [Indexed: 11/13/2022]
Abstract
Recently, the quantum topological energy partitioning method called interacting quantum atoms (IQA) has been extended to MPn (n = 2, 3, 4) wave functions. This enables the extraction of chemical insight related to dynamic electron correlation. The large computational expense of the IQA-MPn approach is compensated by the advantages that IQA offers compared to older nontopological energy decomposition schemes. This expense is problematic in the construction of a machine learning training set to create kriging models for topological atoms. However, the algorithm presented here markedly accelerates the calculation of atomically partitioned electron correlation energies. Then again, the algorithm cannot calculate pairwise interatomic energies because it applies analytical integrals over whole space (rather than over atomic volumes). However, these pairwise energies are not needed in the quantum topological force field FFLUX, which only uses the energy of an atom interacting with all remaining atoms of the system that it is part of. Thus, it is now feasible to generate accurate and sizeable training sets at MPn level of theory. © 2019 The Authors. Journal of Computational Chemistry published by Wiley Periodicals, Inc.
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Affiliation(s)
- Mark A. Vincent
- Manchester Institute of BiotechnologyThe University of ManchesterManchesterM1 7DNUK
- School of ChemistryThe University of ManchesterManchesterM13 9PLUK
| | - Arnaldo F. Silva
- Manchester Institute of BiotechnologyThe University of ManchesterManchesterM1 7DNUK
- School of ChemistryThe University of ManchesterManchesterM13 9PLUK
| | - Paul L. A. Popelier
- Manchester Institute of BiotechnologyThe University of ManchesterManchesterM1 7DNUK
- School of ChemistryThe University of ManchesterManchesterM13 9PLUK
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24
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Bučinský L, Jayatilaka D, Grabowsky S. Relativistic quantum crystallography of diphenyl- and dicyanomercury. Theoretical structure factors and Hirshfeld atom refinement. Acta Crystallogr A Found Adv 2019; 75:705-717. [PMID: 31475915 DOI: 10.1107/s2053273319008027] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 06/04/2019] [Indexed: 11/10/2022]
Abstract
Quantum crystallographic refinement of heavy-element-containing compounds is a challenge, because many physical effects have to be accounted for adequately. Here, the impact and magnitude of relativistic effects are compared with those of electron correlation, polarization through the environment, choice of basis set and treatment of thermal motion effects on the structure factors of diphenylmercury(II) [Hg(Ph)2] and dicyanomercury(II) [Hg(CN)2]. Furthermore, the individual atomic contributions to the structure factors are explored in detail (using Mulliken population analysis and the exponential decay of atomic displacement parameters) to compare the contributions of lighter atoms, especially hydrogen atoms, against mercury. Subsequently, relativistic Hirshfeld atom refinement (HAR) is validated against theoretical structure factors of Hg(Ph)2 and Hg(CN)2, starting from perturbed geometries, to test if the relativistic variant of HAR leads to multiple solutions. Generally, relativistic HAR is successful, leading to a perfect match with the reference geometries, but some limitations are pointed out.
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Affiliation(s)
- Lukáš Bučinský
- Institute of Physical Chemistry and Chemical Physics FCHPT, Slovak University of Technology, Radlinskeho 9, Bratislava SK-812 37, Slovakia
| | - Dylan Jayatilaka
- School of Chemistry and Biochemistry, The University of Western Australia, 35 Stirling Highway, Perth WA 6009, Australia
| | - Simon Grabowsky
- Institute of Inorganic Chemistry and Crystallography, Department 2 - Biology/Chemistry, University of Bremen, Leobener Strasse 3, 28359 Bremen, Germany
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25
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Rodríguez-Mayorga M, Ramos-Cordoba E, Lopez X, Solà M, Ugalde JM, Matito E. The Coulomb Hole of the Ne Atom. ChemistryOpen 2019; 8:411-417. [PMID: 30976484 PMCID: PMC6442706 DOI: 10.1002/open.201800235] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 12/20/2018] [Indexed: 11/10/2022] Open
Abstract
We analyze the Coulomb hole of Ne from highly-accurate CISD wave functions obtained from optimized even-tempered basis sets. Using a two-fold extrapolation procedure we obtain highly accurate results that recover 97 % of the correlation energy. We confirm the existence of a shoulder in the short-range region of the Coulomb hole of the Ne atom, which is due to an internal reorganization of the K-shell caused by electron correlation of the core electrons. The feature is very sensitive to the quality of the basis set in the core region and it is not exclusive to Ne, being also present in most of second-row atoms, thus confirming that it is due to K-shell correlation effects.
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Affiliation(s)
- Mauricio Rodríguez-Mayorga
- Kimika Fakultatea Euskal Herriko Unibertsitatea (UPV/EHU) Donostia International Physics Center (DIPC) P.K. 1072 20080 Donostia, Euskadi Spain E-mail: eloy.raco_at_gmail.com.,Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química University of Girona C/ Maria Aurèlia Capmany, 69 17003 Girona Catalonia Spain
| | - Eloy Ramos-Cordoba
- Kimika Fakultatea Euskal Herriko Unibertsitatea (UPV/EHU) Donostia International Physics Center (DIPC) P.K. 1072 20080 Donostia, Euskadi Spain E-mail: eloy.raco_at_gmail.com
| | - Xabier Lopez
- Kimika Fakultatea Euskal Herriko Unibertsitatea (UPV/EHU) Donostia International Physics Center (DIPC) P.K. 1072 20080 Donostia, Euskadi Spain E-mail: eloy.raco_at_gmail.com
| | - Miquel Solà
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química University of Girona C/ Maria Aurèlia Capmany, 69 17003 Girona Catalonia Spain
| | - Jesus M Ugalde
- Kimika Fakultatea Euskal Herriko Unibertsitatea (UPV/EHU) Donostia International Physics Center (DIPC) P.K. 1072 20080 Donostia, Euskadi Spain E-mail: eloy.raco_at_gmail.com
| | - Eduard Matito
- Kimika Fakultatea Euskal Herriko Unibertsitatea (UPV/EHU) Donostia International Physics Center (DIPC) P.K. 1072 20080 Donostia, Euskadi Spain E-mail: eloy.raco_at_gmail.com.,IKERBASQUE, Basque Foundation for Science 48011 Bilbao, Euskadi Spain
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26
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Repetsky S, Vyshyvana I, Nakazawa Y, Kruchinin S, Bellucci S. Electron Transport in Carbon Nanotubes with Adsorbed Chromium Impurities. Materials (Basel) 2019; 12:ma12030524. [PMID: 30744176 PMCID: PMC6384842 DOI: 10.3390/ma12030524] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 01/26/2019] [Accepted: 01/30/2019] [Indexed: 12/03/2022]
Abstract
We employ Green’s function method for describing multiband models with magnetic impurities and apply the formalism to the problem of chromium impurities adsorbed onto a carbon nanotube. Density functional theory is used to determine the bandstructure, which is then fit to a tight-binding model to allow for the subsequent Green’s function description. Electron–electron interactions, electron–phonon coupling, and disorder scattering are all taken into account (perturbatively) with a theory that involves a cluster extension of the coherent potential approximation. We show how increasing the cluster size produces more accurate results and how the final calculations converge as a function of the cluster size. We examine the spin-polarized electrical current on the nanotube generated by the magnetic impurities adsorbed onto the nanotube surface. The spin polarization increases with both increasing concentration of chromium impurities and with increasing magnetic field. Its origin arises from the strong electron correlations generated by the Cr impurities.
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Affiliation(s)
- Stanislav Repetsky
- Institute of High Technologies, Taras Shevchenko Kyiv National University, 02033 Kyiv, Ukraine.
| | - Iryna Vyshyvana
- Institute of High Technologies, Taras Shevchenko Kyiv National University, 02033 Kyiv, Ukraine.
| | - Yasuhiro Nakazawa
- Department of Chemistry, Graduate School of Science, Osaka University, 560-0043 Osaka, Japan.
| | - Sergei Kruchinin
- Bogolyubov Institute for Theoretical Physics, 03143 Kyiv, Ukraine.
| | - Stefano Bellucci
- INFN-Laboratori Nazionali di Frascati, Via E. Fermi 40, 00044 Frascati, Italy.
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27
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Baskerville AL, King AW, Cox H. Electron correlation in Li +, He, H - and the critical nuclear charge system Z C : energies, densities and Coulomb holes. R Soc Open Sci 2019; 6:181357. [PMID: 30800382 PMCID: PMC6366201 DOI: 10.1098/rsos.181357] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 11/06/2018] [Indexed: 06/09/2023]
Abstract
This paper presents high-accuracy correlation energies, intracule densities and Coulomb hole(s) for the lithium cation, helium, hydride ion and the system with the critical nuclear charge, Z C , for binding two electrons. The fully correlated (FC) wave function and the Hartree-Fock (HF) wave function are both determined using a Laguerre-based wave function. It is found that for the lithium cation and the helium atom a secondary Coulomb hole is present, in agreement with a previous literature finding, confirming a counterintuitive conclusion that electron correlation can act to bring distant electrons closer together. However, no evidence for a tertiary Coulomb hole is found. For the hydride anion and the system just prior to electron detachment only a single Coulomb hole is present and electron correlation decreases the probability of finding the electrons closer together at all radial distances. The emergence of a secondary Coulomb hole is investigated and found to occur between Z = 1.15 and Z = 1.20. The FC and HF energies and intracule densities (in atomic units) used to calculate the correlation energy and Coulomb hole, respectively, are accurate to at least the nano-scale for helium and the cation and at least the micro-scale for the anions.
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Affiliation(s)
| | | | - Hazel Cox
- Department of Chemistry, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QJ, UK
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28
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Ishikawa T, Sakakura K, Mochizuki Y. RI-MP3 calculations of biomolecules based on the fragment molecular orbital method. J Comput Chem 2018; 39:1970-1978. [PMID: 30277590 DOI: 10.1002/jcc.25368] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 05/04/2018] [Accepted: 05/09/2018] [Indexed: 12/24/2022]
Abstract
In this study, the third-order Møller-Plesset perturbation (MP3) theory using the resolution of the identity (RI) approximation was combined with the fragment molecular orbital (FMO) method to efficiently calculate a high-order electron correlation energy of biomolecular systems. We developed a new algorithm for the RI-MP3 calculation, which can be used with the FMO scheme. After test calculations using a small molecule, the FMO-RI-MP3 calculations were performed for two biomolecular systems comprising a protein and a ligand. The computational cost of these calculations was only around 5 and 4 times higher than those of the FMO-RHF calculations. The error associated with the RI approximation was around 2.0% of the third-order correlation contribution to the total energy. However, the RI approximation error in the interaction energy between the protein and ligand molecule was insignificantly small, which reflected the negligible error in the inter fragment interaction energy. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Takeshi Ishikawa
- Department of Molecular Microbiology and Immunology, Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
| | - Kota Sakakura
- 1st Government and Public Solutions Division, NEC Corporation, 7-1, Shiba 5-chome, Minato-ku, Tokyo, 108-8001, Japan
| | - Yuji Mochizuki
- Department of Chemistry and Research Center for Smart Molecules, Faculty of Science, Rikkyo University, 3-34-1 Nishi-ikebukuro, Toshima-ku, Tokyo, 171-8501, Japan.,Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan
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29
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King AW, Baskerville AL, Cox H. Hartree-Fock implementation using a Laguerre-based wave function for the ground state and correlation energies of two-electron atoms. Philos Trans A Math Phys Eng Sci 2018; 376:rsta.2017.0153. [PMID: 29431681 DOI: 10.1098/rsta.2017.0153] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/25/2017] [Indexed: 06/08/2023]
Abstract
An implementation of the Hartree-Fock (HF) method using a Laguerre-based wave function is described and used to accurately study the ground state of two-electron atoms in the fixed nucleus approximation, and by comparison with fully correlated (FC) energies, used to determine accurate electron correlation energies. A variational parameter A is included in the wave function and is shown to rapidly increase the convergence of the energy. The one-electron integrals are solved by series solution and an analytical form is found for the two-electron integrals. This methodology is used to produce accurate wave functions, energies and expectation values for the helium isoelectronic sequence, including at low nuclear charge just prior to electron detachment. Additionally, the critical nuclear charge for binding two electrons within the HF approach is calculated and determined to be ZHFC=1.031 177 528.This article is part of the theme issue 'Modern theoretical chemistry'.
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Affiliation(s)
- Andrew W King
- Department of Chemistry, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QJ, UK
| | - Adam L Baskerville
- Department of Chemistry, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QJ, UK
| | - Hazel Cox
- Department of Chemistry, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QJ, UK
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30
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Pinter B, Chankisjijev A, Geerlings P, Harvey JN, De Proft F. Conceptual Insights into DFT Spin-State Energetics of Octahedral Transition-Metal Complexes through a Density Difference Analysis. Chemistry 2017; 24:5281-5292. [PMID: 29114944 DOI: 10.1002/chem.201704657] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Indexed: 11/08/2022]
Abstract
In this study, an intuitive concept is derived, which explains the characteristic dependence of spin-state energetics on the exact exchange admixture of DFT functionals in the case of octahedral transition metal complexes. The change in electron density distributions upon varying the admixture, c3 , in the B3LYP functional is analyzed for archetype ionic and covalent systems as well as for the Fe2+ ion in an ideal octahedral field. An understanding of how the DFT description of the electronic structure of octahedral complexes changes as a function of c3 is sought. A systematic spin-state energy analysis of 50 octahedral complexes of various metals and ligands with consistent experimental data is presented, allowing the derivation, in theory, of an optimal c3 value for each system. The notion that the admixture dependence of DFT spin-state energetics stems from the treatment of nondynamic electrons arising from the mixing of (M-Lz2 )0 (dz2 )2 and (M-Lx2-y2 )0 (dx2-y2 )2 configurations into the dominant (M-Lx2-y2 )2 (dx2-y2 )0 and (M-Lx2-y2 )2 (dx2-y2 )0 ones in the low(er) spin states is put forward. That is, in the effort to mimic such electron-electron interactions, ExLDA overestimates, whereas exact exchange downplays the contribution of this type of electron correlation to the stability of low(er) spin states, leading to the widespread practical observation that the higher the exact exchange admixture, the more stable the high-spin-state configuration.
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Affiliation(s)
- Balazs Pinter
- Eenheid Algemene Chemie, Vrije Universiteit Brussel, Faculteit Wetenschappen, Pleinlaan 2, 1050, Brussels, Belgium
| | - Artiom Chankisjijev
- Eenheid Algemene Chemie, Vrije Universiteit Brussel, Faculteit Wetenschappen, Pleinlaan 2, 1050, Brussels, Belgium
| | - Paul Geerlings
- Eenheid Algemene Chemie, Vrije Universiteit Brussel, Faculteit Wetenschappen, Pleinlaan 2, 1050, Brussels, Belgium
| | - Jeremy N Harvey
- Department of Chemistry, KU Leuven, Celestijnenlaan 200F, 3001, Leuven, Belgium
| | - Frank De Proft
- Eenheid Algemene Chemie, Vrije Universiteit Brussel, Faculteit Wetenschappen, Pleinlaan 2, 1050, Brussels, Belgium
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31
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Silva AF, Vincent MA, McDonagh JL, Popelier PLA. The Transferability of Topologically Partitioned Electron Correlation Energies in Water Clusters. Chemphyschem 2017; 18:3360-3368. [PMID: 29094804 DOI: 10.1002/cphc.201700890] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 09/21/2017] [Indexed: 11/06/2022]
Abstract
The electronic effects that govern the cohesion of water clusters are complex, demanding the inclusion of N-body, Coulomb, exchange and correlation effects. Here we present a much needed quantitative study of the effect of correlation (and hence dispersion) energy on the stabilization of water clusters. For this purpose we used a topological energy partitioning method called Interacting Quantum Atoms (IQA) to partition water clusters into topological atoms, based on a MP2/6-31G(d,p) wave function, and modified versions of GAUSSIAN09 and the Quantum Chemical Topology (QCT) program MORFI. Most of the cohesion in the water clusters provided by electron correlation comes from intramolecular energy stabilization. Hydrogen bond-related interactions tend to largely cancel each other. Electron correlation energies are transferable in almost all instances within 1 kcal mol-1 . This observed transferability is very important to the further development of the QCT force field FFLUX, especially to the future modelling of liquid water.
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Affiliation(s)
- Arnaldo F Silva
- Manchester Institute of Biotechnology (MIB), the University of Manchester, 131 Princess Street, Manchester, M1 7DN, Great Britain), Fax: (+44) 161 3064511.,School of Chemistry, the University of Manchester, Oxford Road, Manchester, M13 9PL, Great Britain
| | - Mark A Vincent
- Manchester Institute of Biotechnology (MIB), the University of Manchester, 131 Princess Street, Manchester, M1 7DN, Great Britain), Fax: (+44) 161 3064511.,School of Chemistry, the University of Manchester, Oxford Road, Manchester, M13 9PL, Great Britain
| | - James L McDonagh
- Manchester Institute of Biotechnology (MIB), the University of Manchester, 131 Princess Street, Manchester, M1 7DN, Great Britain), Fax: (+44) 161 3064511.,School of Chemistry, the University of Manchester, Oxford Road, Manchester, M13 9PL, Great Britain
| | - Paul L A Popelier
- Manchester Institute of Biotechnology (MIB), the University of Manchester, 131 Princess Street, Manchester, M1 7DN, Great Britain), Fax: (+44) 161 3064511.,School of Chemistry, the University of Manchester, Oxford Road, Manchester, M13 9PL, Great Britain
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32
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Hahn T, Ludwig T, Timm C, Kortus J. Electronic structure, transport, and collective effects in molecular layered systems. Beilstein J Nanotechnol 2017; 8:2094-2105. [PMID: 29090111 PMCID: PMC5647717 DOI: 10.3762/bjnano.8.209] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 09/08/2017] [Indexed: 06/07/2023]
Abstract
The great potential of organic heterostructures for organic device applications is exemplified by the targeted engineering of the electronic properties of phthalocyanine-based systems. The transport properties of two different phthalocyanine systems, a pure copper phthalocyanine (CoPc) and a flourinated copper phthalocyanine-manganese phthalocyanine (F16CoPc/MnPc) heterostructure, are investigated by means of density functional theory (DFT) and the non-equilibrium Green's function (NEGF) approach. Furthermore, a master-equation-based approach is used to include electronic correlations beyond the mean-field-type approximation of DFT. We describe the essential theoretical tools to obtain the parameters needed for the master equation from DFT results. Finally, an interacting molecular monolayer is considered within a master-equation approach.
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Affiliation(s)
- Torsten Hahn
- Institute of Theoretical Physics, TU Freiberg, Leipziger Str. 23, D-09599 Freiberg, Germany
| | - Tim Ludwig
- Institute of Theoretical Physics, Technische Universität Dresden, 01062 Dresden, Germany
| | - Carsten Timm
- Institute of Theoretical Physics, Technische Universität Dresden, 01062 Dresden, Germany
| | - Jens Kortus
- Institute of Theoretical Physics, TU Freiberg, Leipziger Str. 23, D-09599 Freiberg, Germany
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33
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Huang W, Jiang N, Schwarz WHE, Yang P, Li J. Diversity of Chemical Bonding and Oxidation States in MS 4 Molecules of Group 8 Elements. Chemistry 2017; 23:10580-10589. [PMID: 28516506 DOI: 10.1002/chem.201701117] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Indexed: 11/11/2022]
Abstract
The geometric and electronic ground-state structures of 30 isomers of six MS4 molecules (M=Group 8 metals Fe, Ru, Os, Hs, Sm, and Pu) have been studied by using quantum-chemical density functional theory and correlated wavefunction approaches. The MS4 species were compared to analogous MO4 species recently investigated (W. Huang, W.-H. Xu, W. H. E. Schwarz, J. Li, Inorg. Chem. 2016, 55, 4616). A metal oxidation state (MOS) with a high value of eight appeared in the low-spin singlet Td geometric species (Os,Hs)S4 and (Ru,Os,Hs)O4 , whereas a low MOS of two appeared in the high-spin septet D2d species Fe(S2 )2 and (slightly excited) metastable Fe(O2 )2 . The ground states of all other molecules had intermediate MOS values, with S2- , S22- , S21- (and O2- , O1- , O22- , O21- ) ligands bonded by ionic, covalent, and correlative contributions. The known tendencies toward lower MOS on going from oxides to sulfides, from Hs to Os to Ru, and from Pu to Sm, and the specific behavior of Fe, were found to arise from the different atomic orbital energies and radii of the (n-1)p core and (n-1)d and (n-2)f valence shells of the metal atoms in row n of the periodic table. The comparative results of the electronic and geometric structures of the MO4 and MS4 species provides insight into the periodicity of oxidation states and bonding.
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Affiliation(s)
- Wei Huang
- Department of Chemistry and Key Laboratory of Organic Optoelectronics & Molecular Engineering of the Ministry of Education, Tsinghua University, Beijing, 100084, P.R. China
| | - Ning Jiang
- Department of Chemistry and Key Laboratory of Organic Optoelectronics & Molecular Engineering of the Ministry of Education, Tsinghua University, Beijing, 100084, P.R. China
| | - W H Eugen Schwarz
- Department of Chemistry and Key Laboratory of Organic Optoelectronics & Molecular Engineering of the Ministry of Education, Tsinghua University, Beijing, 100084, P.R. China.,Physical and Theoretical Chemistry, University of Siegen, Siegen, 57068, Germany
| | - Ping Yang
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, USA.,Environmental Molecular Science Laboratory, Pacific Northwest National Laboratory, Richland, Washington, 953002, USA
| | - Jun Li
- Department of Chemistry and Key Laboratory of Organic Optoelectronics & Molecular Engineering of the Ministry of Education, Tsinghua University, Beijing, 100084, P.R. China.,Environmental Molecular Science Laboratory, Pacific Northwest National Laboratory, Richland, Washington, 953002, USA
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34
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Genoni A, Dos Santos LHR, Meyer B, Macchi P. Can X-ray constrained Hartree-Fock wavefunctions retrieve electron correlation? IUCrJ 2017; 4:136-146. [PMID: 28250952 PMCID: PMC5330524 DOI: 10.1107/s2052252516019217] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 12/02/2016] [Indexed: 05/29/2023]
Abstract
The X-ray constrained wavefunction (XC-WF) method proposed by Jayatilaka [Jayatilaka & Grimwood (2001) ▸, Acta Cryst. A57, 76-86] has attracted much attention because it represents a possible third way of theoretically studying the electronic structure of atoms and molecules, combining features of the more popular wavefunction- and DFT-based approaches. In its original formulation, the XC-WF technique extracts statistically plausible wavefunctions from experimental X-ray diffraction data of molecular crystals. A weight is used to constrain the pure Hartree-Fock solution to the observed X-ray structure factors. Despite the wavefunction being a single Slater determinant, it is generally assumed that its flexibility could guarantee the capture, better than any other experimental model, of electron correlation effects, absent in the Hartree-Fock Hamiltonian but present in the structure factors measured experimentally. However, although the approach has been known for long time, careful testing of this fundamental hypothesis is still missing. Since a formal demonstration is impossible, the validation can only be done heuristically and, to accomplish this task, X-ray constrained Hartree-Fock calculations have been performed using structure factor amplitudes computed at a very high correlation level (coupled cluster) for selected molecules in isolation, in order to avoid the perturbations due to intermolecular interactions. The results show that a single-determinant XC-WF is able to capture the electron correlation effects only partially. The largest amount of electron correlation is extracted when: (i) a large external weight is used (much larger than what has normally been used in XC-WF calculations using experimental data); and (ii) the high-order reflections, which carry less information on the electron correlation, are down-weighted (or even excluded), otherwise they would bias the fitting towards the unconstrained Hartree-Fock wavefunction.
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Affiliation(s)
- Alessandro Genoni
- CNRS, Laboratoire SRSMC, UMR 7565, Boulevard des Aiguillettes, BP 70239, Vandoeuvre-lès-Nancy, F-54506, France
- Université de Lorraine, Laboratoire SRSMC, UMR 7565, Boulevard des Aiguillettes, BP 70239, Vandoeuvre-lès-Nancy, F-54506, France
| | - Leonardo H. R. Dos Santos
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern 3012, Switzerland
| | - Benjamin Meyer
- CNRS, Laboratoire SRSMC, UMR 7565, Boulevard des Aiguillettes, BP 70239, Vandoeuvre-lès-Nancy, F-54506, France
- Université de Lorraine, Laboratoire SRSMC, UMR 7565, Boulevard des Aiguillettes, BP 70239, Vandoeuvre-lès-Nancy, F-54506, France
| | - Piero Macchi
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern 3012, Switzerland
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35
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Takabayashi Y, Prassides K. Unconventional high-Tc superconductivity in fullerides. Philos Trans A Math Phys Eng Sci 2016; 374:rsta.2015.0320. [PMID: 27501971 PMCID: PMC4978744 DOI: 10.1098/rsta.2015.0320] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/27/2016] [Indexed: 06/06/2023]
Abstract
A3C60 molecular superconductors share a common electronic phase diagram with unconventional high-temperature superconductors such as the cuprates: superconductivity emerges from an antiferromagnetic strongly correlated Mott-insulating state upon tuning a parameter such as pressure (bandwidth control) accompanied by a dome-shaped dependence of the critical temperature, Tc However, unlike atom-based superconductors, the parent state from which superconductivity emerges solely by changing an electronic parameter-the overlap between the outer wave functions of the constituent molecules-is controlled by the C60 (3-) molecular electronic structure via the on-molecule Jahn-Teller effect influence of molecular geometry and spin state. Destruction of the parent Mott-Jahn-Teller state through chemical or physical pressurization yields an unconventional Jahn-Teller metal, where quasi-localized and itinerant electron behaviours coexist. Localized features gradually disappear with lattice contraction and conventional Fermi liquid behaviour is recovered. The nature of the underlying (correlated versus weak-coupling Bardeen-Cooper-Schrieffer theory) s-wave superconducting states mirrors the unconventional/conventional metal dichotomy: the highest superconducting critical temperature occurs at the crossover between Jahn-Teller and Fermi liquid metal when the Jahn-Teller distortion melts.This article is part of the themed issue 'Fullerenes: past, present and future, celebrating the 30th anniversary of Buckminster Fullerene'.
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Affiliation(s)
- Yasuhiro Takabayashi
- World Premier International-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Kosmas Prassides
- World Premier International-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
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36
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Aquilante F, Autschbach J, Carlson RK, Chibotaru LF, Delcey MG, De Vico L, Fdez Galván I, Ferré N, Frutos LM, Gagliardi L, Garavelli M, Giussani A, Hoyer CE, Li Manni G, Lischka H, Ma D, Malmqvist PÅ, Müller T, Nenov A, Olivucci M, Pedersen TB, Peng D, Plasser F, Pritchard B, Reiher M, Rivalta I, Schapiro I, Segarra-Martí J, Stenrup M, Truhlar DG, Ungur L, Valentini A, Vancoillie S, Veryazov V, Vysotskiy VP, Weingart O, Zapata F, Lindh R. Molcas 8: New capabilities for multiconfigurational quantum chemical calculations across the periodic table. J Comput Chem 2015; 37:506-41. [PMID: 26561362 DOI: 10.1002/jcc.24221] [Citation(s) in RCA: 1083] [Impact Index Per Article: 120.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 09/07/2015] [Accepted: 09/09/2015] [Indexed: 12/17/2022]
Abstract
In this report, we summarize and describe the recent unique updates and additions to the Molcas quantum chemistry program suite as contained in release version 8. These updates include natural and spin orbitals for studies of magnetic properties, local and linear scaling methods for the Douglas-Kroll-Hess transformation, the generalized active space concept in MCSCF methods, a combination of multiconfigurational wave functions with density functional theory in the MC-PDFT method, additional methods for computation of magnetic properties, methods for diabatization, analytical gradients of state average complete active space SCF in association with density fitting, methods for constrained fragment optimization, large-scale parallel multireference configuration interaction including analytic gradients via the interface to the Columbus package, and approximations of the CASPT2 method to be used for computations of large systems. In addition, the report includes the description of a computational machinery for nonlinear optical spectroscopy through an interface to the QM/MM package Cobramm. Further, a module to run molecular dynamics simulations is added, two surface hopping algorithms are included to enable nonadiabatic calculations, and the DQ method for diabatization is added. Finally, we report on the subject of improvements with respects to alternative file options and parallelization.
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Affiliation(s)
- Francesco Aquilante
- Department of Chemistry - Ångström, The Theoretical Chemistry Programme, Uppsala University, Box 518, Uppsala, 751 20, Sweden.,Dipartimento di Chimica "G. Ciamician", Università di Bologna, via Selmi 2, IT-40126, Bologna, Italy
| | - Jochen Autschbach
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, New York, 14260-3000, USA
| | - Rebecca K Carlson
- Department of Chemistry, Supercomputing Institute, and Chemical Theory Center, University of Minnesota, Minneapolis, Minnesota, 55455-0431, USA
| | - Liviu F Chibotaru
- Division of Quantum and Physical Chemistry, and INPAC, Institute for Nanoscale Physics and Chemistry, Katholieke Universiteit Leuven Celestijnenlaan, 200F, 3001, Belgium
| | - Mickaël G Delcey
- Department of Chemistry - Ångström, The Theoretical Chemistry Programme, Uppsala University, Box 518, Uppsala, 751 20, Sweden
| | - Luca De Vico
- Department of Chemistry, Copenhagen University, Universitetsparken 5, Copenhagen Ø, 2100, Denmark
| | - Ignacio Fdez Galván
- Department of Chemistry - Ångström, The Theoretical Chemistry Programme, Uppsala University, Box 518, Uppsala, 751 20, Sweden.,Uppsala Center for Computational Chemistry - UC3, Uppsala University, Box 518, Uppsala, 751 20, Sweden
| | - Nicolas Ferré
- Université d'Aix-Marseille, CNRS, Institut de Chimie Radicalaire, Campus Étoile/Saint-Jérôme Case 521, Avenue Esc. Normandie Niemen, Marseille Cedex 20, 13397, France
| | - Luis Manuel Frutos
- Unidad Docente de Química Física, Universidad de Alcalá, E-28871 Alcalá de Henares, Madrid, Spain
| | - Laura Gagliardi
- Department of Chemistry, Supercomputing Institute, and Chemical Theory Center, University of Minnesota, Minneapolis, Minnesota, 55455-0431, USA
| | - Marco Garavelli
- Dipartimento di Chimica "G. Ciamician", Università di Bologna, via Selmi 2, IT-40126, Bologna, Italy.,Université de Lyon, CNRS, École Normale Supérieure de Lyon, 46 Allée d'Italie, Lyon Cedex 07, F-69364, France
| | - Angelo Giussani
- Dipartimento di Chimica "G. Ciamician", Università di Bologna, via Selmi 2, IT-40126, Bologna, Italy
| | - Chad E Hoyer
- Department of Chemistry, Supercomputing Institute, and Chemical Theory Center, University of Minnesota, Minneapolis, Minnesota, 55455-0431, USA
| | - Giovanni Li Manni
- Department of Chemistry, Supercomputing Institute, and Chemical Theory Center, University of Minnesota, Minneapolis, Minnesota, 55455-0431, USA.,Max Planck Institut für Festkörperforschung, Heisenbergstraße 1, Stuttgart, 70569, Germany
| | - Hans Lischka
- Department of Chemistry and Biochemistry, Texas Tech University, Memorial Circle and Boston, Lubbock, Texas, 79409-1061, USA.,Institute for Theoretical Chemistry, University of Vienna, Währingerstraße 17, Vienna, A-1090, Austria
| | - Dongxia Ma
- Department of Chemistry, Supercomputing Institute, and Chemical Theory Center, University of Minnesota, Minneapolis, Minnesota, 55455-0431, USA.,Max Planck Institut für Festkörperforschung, Heisenbergstraße 1, Stuttgart, 70569, Germany
| | - Per Åke Malmqvist
- Department of Theoretical Chemistry, Lund University, Chemical Center, P.O.B 124 S-221 00, Lund, Sweden
| | - Thomas Müller
- Jülich Supercomputing Centre (JSC), Forschungszentrum Jülich GmbH, Institute for Advanced Simulation (IAS), Wilhelm-Johnen-Straße, Jülich, 52425, Germany
| | - Artur Nenov
- Dipartimento di Chimica "G. Ciamician", Università di Bologna, via Selmi 2, IT-40126, Bologna, Italy
| | - Massimo Olivucci
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, via Aldo Moro 2, Siena, 53100, Italy.,Chemistry Department, Bowling Green State University, 141 Overman Hall, Bowling Green, Ohio, 43403, USA.,Institut de Physique et Chimie des Matériaux de Strasbourg & Labex NIE, Université de Strasbourg, CNRS UMR 7504, 23 Rue du Loess, Strasbourg, 67034, France
| | - Thomas Bondo Pedersen
- Centre for Theoretical and Computational Chemistry, Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, Oslo, 0315, Norway
| | - Daoling Peng
- College of Chemistry and Environment, South China Normal University, Guangzhou, 510006, China
| | - Felix Plasser
- Institute for Theoretical Chemistry, University of Vienna, Währingerstraße 17, Vienna, A-1090, Austria
| | - Ben Pritchard
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, New York, 14260-3000, USA
| | - Markus Reiher
- ETH Zurich, Laboratorium für Physikalische Chemie, Vladimir-Prelog-Weg 2, Zurich, CH-8093, Switzerland
| | - Ivan Rivalta
- Université de Lyon, CNRS, École Normale Supérieure de Lyon, 46 Allée d'Italie, Lyon Cedex 07, F-69364, France
| | - Igor Schapiro
- Institut de Physique et Chimie des Matériaux de Strasbourg & Labex NIE, Université de Strasbourg, CNRS UMR 7504, 23 Rue du Loess, Strasbourg, 67034, France.,Fritz Haber Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - Javier Segarra-Martí
- Dipartimento di Chimica "G. Ciamician", Università di Bologna, via Selmi 2, IT-40126, Bologna, Italy
| | - Michael Stenrup
- Department of Chemistry - Ångström, The Theoretical Chemistry Programme, Uppsala University, Box 518, Uppsala, 751 20, Sweden.,Uppsala Center for Computational Chemistry - UC3, Uppsala University, Box 518, Uppsala, 751 20, Sweden
| | - Donald G Truhlar
- Department of Chemistry, Supercomputing Institute, and Chemical Theory Center, University of Minnesota, Minneapolis, Minnesota, 55455-0431, USA
| | - Liviu Ungur
- Division of Quantum and Physical Chemistry, and INPAC, Institute for Nanoscale Physics and Chemistry, Katholieke Universiteit Leuven Celestijnenlaan, 200F, 3001, Belgium
| | - Alessio Valentini
- Unidad Docente de Química Física, Universidad de Alcalá, E-28871 Alcalá de Henares, Madrid, Spain.,Department of Biotechnology, Chemistry and Pharmacy, University of Siena, via Aldo Moro 2, Siena, 53100, Italy
| | - Steven Vancoillie
- Department of Theoretical Chemistry, Lund University, Chemical Center, P.O.B 124 S-221 00, Lund, Sweden
| | - Valera Veryazov
- Department of Theoretical Chemistry, Lund University, Chemical Center, P.O.B 124 S-221 00, Lund, Sweden
| | - Victor P Vysotskiy
- Department of Theoretical Chemistry, Lund University, Chemical Center, P.O.B 124 S-221 00, Lund, Sweden
| | - Oliver Weingart
- Institut für Theoretische Chemie und Computerchemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, Düsseldorf, 40225, Germany
| | - Felipe Zapata
- Unidad Docente de Química Física, Universidad de Alcalá, E-28871 Alcalá de Henares, Madrid, Spain
| | - Roland Lindh
- Department of Chemistry - Ångström, The Theoretical Chemistry Programme, Uppsala University, Box 518, Uppsala, 751 20, Sweden.,Uppsala Center for Computational Chemistry - UC3, Uppsala University, Box 518, Uppsala, 751 20, Sweden
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Machado FBC, Aquino AJA, Lischka H. The diverse manifold of electronic states generated by a single carbon defect in a graphene sheet: multireference calculations using a pyrene defect model. Chemphyschem 2014; 15:3334-41. [PMID: 25044651 DOI: 10.1002/cphc.201402304] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Indexed: 11/08/2022]
Abstract
Detailed calculations have been performed on the electronic states occurring in a single vacancy defect model based on pyrene from which one of the central carbon atoms has been removed. Complete active space self-consistent field and multireference configuration interaction with singles and doubles calculations have been performed using the 6-31G and 6-31G* basis sets. Two types of defect geometries have been defined: 1) The unrelaxed defect structure based on pyrene and 2) a relaxed structure. In total 12 electronic states have been computed for the unrelaxed structure at C2v symmetry, comprising four singlets, triplets and quintets each. The lowest six states are formed from singlet and triplet states and appear in a rather narrow gap of ∼0.6 eV. The lowest quintet state is found 1.43 eV above the (3) B1 ground state. As predicted from Jahn-Teller distortions, a CC bond is formed between dangling carbon bonds in the (1, 3) B1 states, leading to the formation of a five-membered ring. The (1, 3) A2 states show initial repulsive behavior along the bond formation coordinate until an avoided crossing is reached by which these states are furnished with CC bonding character so that finally also in these cases a CC bond is established. Linear interpolation curves between the initial unrelaxed defect structure and the final optimized structure are used to give an overview of the evolution of electronic states and the occurrence of avoided crossings. Out-of-plane structures are investigated with special emphasis on the carbon atom containing a dangling bond in the relaxed structure. Unpaired electron densities are used to characterize the electronic structure of the different states.
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Affiliation(s)
- Francisco B C Machado
- Departamento de Química, Instituto Tecnológico de Aeronáutica, São José dos Campos, 12228-900, São Paulo (Brazil); Current address: Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409-1061 (USA).
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38
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San-Fabián E, Moscardó F. Cyclobutadiene automerization and rotation of ethylene: energetics of the barriers by using spin-polarized wave functions. J Comput Chem 2014; 35:1356-63. [PMID: 24817406 DOI: 10.1002/jcc.23630] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 04/10/2014] [Accepted: 04/14/2014] [Indexed: 11/08/2022]
Abstract
Spin-projected spin polarized Møller-Plesset and spin polarized coupled clusters calculations have been made to estimate the cyclobutadiene automerization, the ethylene torsion barriers in their ground state, and the gap between the singlet and triplet states of ethylene. The results have been obtained optimizing the geometries at MP4 and/or CCSD levels, by an extensive Gaussian basis set. A comparative analysis with more complex calculations, up to MP5 and CCSDTQP, together with others from the literature, have also been made, showing the efficacy of using spin-polarized wave functions as a reference wave function for Møller-Plesset and coupled clusters calculations, in such problems.
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Affiliation(s)
- Emilio San-Fabián
- Departamento de Química Física, Unidad Asociada del CSIC e Instituto Universitario de Materiales, Universidad de Alicante, San Vicente del Raspeig, 03690, Alicante, Spain
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39
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Abstract
The electron-electron correlation energy is negative, and attractive dispersion interactions are entirely a correlation effect; therefore, the contribution of correlation to intermolecular binding is commonly assumed to be negative, or binding in nature. However, there are many cases where the long-range correlation binding energy is positive, with certain geometries of the water dimer as a prominent example. Geometries with dipoles misaligned can also have an electrostatically dominated, though negative, long-range correlation binding. In either case, the interaction decays as R(-3). This has its origin in the systematic overestimation of dipole moments by Hartree-Fock theory, leading to a reduction in the calculated electrostatic attraction upon inclusion of correlation. Thus, energy decomposition analyses that include correlation but do not correct mean field electrostatic terms are suboptimal. Attenuated second-order Møller-Plesset theory, which smoothly truncates long-range electron correlation effects to zero, can, paradoxically, have the correct long-range behavior for many intermolecular interactions.
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Affiliation(s)
- Jonathan Thirman
- Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Martin Head-Gordon
- Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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40
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Abstract
A systematic investigation of three different electron–electron entanglement measures, namely the von Neumann, the linear and the occupation number entropy at full configuration interaction level has been performed for the four helium-like systems hydride, helium, Li+ and Be2+ using a large number of different basis sets. The convergence behavior of the resulting energies and entropies revealed that the latter do in general not show the expected strictly monotonic increase upon increase of the one–electron basis. Overall, the three different entanglement measures show good agreement among each other, the largest deviations being observed for small basis sets. The data clearly demonstrates that it is important to consider the nature of the chemical system when investigating entanglement phenomena in the framework of Gaussian type basis sets: while in case of hydride the use of augmentation functions is crucial, the application of core functions greatly improves the accuracy in case of cationic systems such as Li+ and Be2+. In addition, numerical derivatives of the entanglement measures with respect to the nucleic charge have been determined, which proved to be a very sensitive probe of the convergence leading to qualitatively wrong results (i.e., the wrong sign) if too small basis sets are used.
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Affiliation(s)
- Thomas S Hofer
- Theoretical Chemistry Division, Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck Innsbruck, Austria
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41
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Abstract
New free-electron laser and high-harmonic generation X-ray light sources are capable of supplying pulses short and intense enough to perform resonant nonlinear time-resolved experiments in molecules. Valence-electron motions can be triggered impulsively by core excitations and monitored with high temporal and spatial resolution. We discuss possible experiments that employ attosecond X-ray pulses to probe the quantum coherence and correlations of valence electrons and holes, rather than the charge density alone, building on the analogy with existing studies of vibrational motions using femtosecond techniques in the visible regime.
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Affiliation(s)
- Shaul Mukamel
- Department of Chemistry, University of California, Irvine, California 92697, USA.
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42
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Yasuzuka S, Murata K. Recent progress in high-pressure studies on organic conductors. Sci Technol Adv Mater 2009; 10:024307. [PMID: 27877280 PMCID: PMC5090437 DOI: 10.1088/1468-6996/10/2/024307] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2008] [Revised: 07/06/2009] [Accepted: 02/10/2009] [Indexed: 06/06/2023]
Abstract
Recent high-pressure studies of organic conductors and superconductors are reviewed. The discovery of the highest Tc superconductivity among organics under high pressure has triggered the further progress of the high-pressure research. Owing to this finding, various organic conductors with the strong electron correlation were investigated under high pressures. This review includes the pressure techniques using the cubic anvil apparatus, as well as high-pressure studies of the organic conductors up to 10 GPa showing extraordinary temperature and pressure dependent transport phenomena.
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Affiliation(s)
- Syuma Yasuzuka
- Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan
| | - Keizo Murata
- Department of Material Science, Graduate School of Science, Osaka City University, Osaka 558-8585, Japan
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Abstract
Two major themes in the physics of condensed matter are quantum critical phenomena and unconventional superconductivity. These usually occur in the context of competing interactions in systems of strongly correlated electrons. All this interesting physics comes together in the behavior of the recently discovered iron pnictide compounds that have generated enormous interest because of their moderately high-temperature superconductivity. The ubiquity of antiferromagnetic ordering in their phase diagrams naturally raises the question of the relevance of magnetic quantum criticality, but the answer remains uncertain both theoretically and experimentally. Here, we show that the undoped iron pnictides feature a unique type of magnetic quantum critical point, which results from a competition between electronic localization and itinerancy. Our theory provides a mechanism to understand the experimentally observed variation of the ordered moment among the undoped iron pnictides. We suggest P substitution for As in the undoped iron pnictides as a means to access this example of magnetic quantum criticality in an unmasked fashion. Our findings point to the iron pnictides as a much-needed setting for quantum criticality, one that offers a unique set of control parameters.
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Affiliation(s)
- Jianhui Dai
- Zhejiang Institute of Modern Physics, Zhejiang University, Hangzhou 310027, China
| | - Qimiao Si
- Department of Physics and Astronomy, Rice University, Houston, TX 77005
| | - Jian-Xin Zhu
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545; and
| | - Elihu Abrahams
- Department of Physics and Astronomy, Center for Materials Theory, Rutgers University, Piscataway, NJ 08855
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