1
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Abstract
Robust organic triradicals with high-spin quartet ground states provide promising applications in molecular magnets, spintronics, etc. In this context, a triradical based on Blatter's radical has been synthesized recently, having two low-lying non-degenerate doublet states with a quartet ground state. The traditional broken-symmetry (BS)-DFT computed doublet-quartet energy gaps are reported to be somewhat overestimated in comparison to the experimentally observed values. In this work, we have employed different ab initio methods on this prototypical system to obtain more accurate doublet-quartet energy gaps for this triradical. The spin-constraint broken-symmetry (CBS)-DFT method has been used to reduce the overestimation of energy gaps from BS-DFT. To address the issues of spin-contamination and the multireference nature of low-spin states affecting the DFT methods, we have computed the energy gaps using appropriately state-averaged CASSCF and NEVPT2 computations. Using a series of active spaces, our calculations are shown to provide quite accurate values in concordance with the experimentally observed results. Furthermore, we have proposed and modeled another two triradicals based on Blatter's radical, which are of interest for experimental synthesis and characterization. Our computations show that all these triradicals also have a quartet ground state with a similar energy difference between the excited doublet states.
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Affiliation(s)
- Rishu Khurana
- Institute of Nano Science and Technology, Sector-81, Mohali, Punjab 140306, India
| | - Ashima Bajaj
- Institute of Nano Science and Technology, Sector-81, Mohali, Punjab 140306, India
| | - K R Shamasundar
- Indian Institute of Science Education and Research Mohali, Sector-81, Mohali, Punjab 140306, India
| | - Md Ehesan Ali
- Institute of Nano Science and Technology, Sector-81, Mohali, Punjab 140306, India
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2
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Pokhilko P, Zgid D. Natural orbitals and two-particle correlators as tools for the analysis of effective exchange couplings in solids. Phys Chem Chem Phys 2023; 25:21267-21279. [PMID: 37548912 DOI: 10.1039/d3cp01975f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Using generalizations of spin-averaged natural orbitals and two-particle charge correlators for solids, we investigate the electronic structure of antiferromagnetic transition-metal oxides with a fully self-consistent, imaginary-time GW method. Our findings disagree with the Goodenough-Kanamori (GK) rules that are commonly used for the qualitative interpretation of such solids. First, we found a strong dependence of the natural orbital occupancies on momenta, contradicting GK assumptions. Second, along the momentum path, the character of natural orbitals changes. In particular, the contributions of oxygen 2s orbitals are important, which has not been considered in the GK rules. To analyze the influence of the electronic correlation on the values of effective exchange coupling constants, we use both natural orbitals and two-particle correlators and show that electronic screening modulates the degree of superexchange by stabilizing the charge-transfer contributions, which greatly affects these coupling constants. Finally, we give a set of predictions and recommendations regarding the use of density functional, Green's function, and wave-function methods for evaluating effective magnetic couplings in molecules and solids.
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Affiliation(s)
- Pavel Pokhilko
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA.
| | - Dominika Zgid
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
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3
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Duplaix-Rata G, Le Guennic B, David G. Revisiting magnetic exchange couplings in heterodinuclear complexes through the decomposition method in KS-DFT. Phys Chem Chem Phys 2023; 25:14170-14178. [PMID: 37162514 DOI: 10.1039/d3cp00697b] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Providing tools to understand the physical mechanisms governing magnetic properties in transition metal-based compounds is still of great interest. Here, the magnetic exchange coupling in a series of heterodinuclear complexes is investigated by means of the decomposition method. This work presents the first application of the decomposition method to systems where magnetic centres may bear more than one unpaired electron. By decomposing the coupling into three physical contributions (direct exchange, kinetic exchange, and spin polarisation), we provide numerical arguments to confirm or infirm the rationalisation allowed by the conceptual analysis of the magnetic d orbitals. We also take advantage of the recently proposed generalisation of the method [David et al., J. Chem. Theory Comput., 2023, 19, 157] to get more insights into the underlying mechanisms by disentangling the coupling between centres into its electron-electron interactions.
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Affiliation(s)
- Gwenhaël Duplaix-Rata
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes)-UMR 6226, F-35000 Rennes, France.
| | - Boris Le Guennic
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes)-UMR 6226, F-35000 Rennes, France.
| | - Grégoire David
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes)-UMR 6226, F-35000 Rennes, France.
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4
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Kotaru S, Kähler S, Alessio M, Krylov AI. Magnetic exchange interactions in binuclear and tetranuclear iron(III) complexes described by spin-flip DFT and Heisenberg effective Hamiltonians. J Comput Chem 2023; 44:367-380. [PMID: 35699152 PMCID: PMC10084445 DOI: 10.1002/jcc.26941] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 04/07/2022] [Accepted: 04/22/2022] [Indexed: 12/31/2022]
Abstract
Low-energy spectra of single-molecule magnets (SMMs) are often described by Heisenberg Hamiltonians. Within this formalism, exchange interactions between magnetic centers determine the ground-state multiplicity and energy separation between the ground and excited states. In this contribution, we extract exchange coupling constants (J) for a set of iron (III) binuclear and tetranuclear complexes from all-electron calculations using non-collinear spin-flip time-dependent density functional theory (NC-SF-TDDFT). For 12 binuclear complexes with J-values ranging from -6 to -132 cm-1 , our benchmark calculations using the short-range hybrid ωPBEh functional and 6-31G(d,p) basis set agree well with the experimentally derived values (mean absolute error of 4.7 cm-1 ). For the tetranuclear SMMs, the computed J constants are within 6 cm-1 from the experimentally derived values. We explore the range of applicability of the Heisenberg model by analyzing bonding patterns in these Fe(III) complexes using natural orbitals (NO), their occupations, and the number of effectively unpaired electrons. The results illustrate the efficiency of the spin-flip protocol for computing the exchange couplings and the utility of the NO analysis in assessing the validity of effective spin Hamiltonians.
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Affiliation(s)
- Saikiran Kotaru
- Department of ChemistryUniversity of Southern CaliforniaLos AngelesCalifornia
| | - Sven Kähler
- Department of ChemistryUniversity of Southern CaliforniaLos AngelesCalifornia
| | - Maristella Alessio
- Department of ChemistryUniversity of Southern CaliforniaLos AngelesCalifornia
| | - Anna I. Krylov
- Department of ChemistryUniversity of Southern CaliforniaLos AngelesCalifornia
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5
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David G, Ferré N, Le Guennic B. Consistent Evaluation of Magnetic Exchange Couplings in Multicenter Compounds in KS-DFT: The Recomposition Method. J Chem Theory Comput 2023; 19:157-173. [PMID: 36475691 DOI: 10.1021/acs.jctc.2c01022] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The use of broken-symmetry calculations in Kohn-Sham density functional theory has offered an affordable route to study magnetic exchange couplings in transition-metal-based compounds. However, computing this property in compounds exhibiting several couplings is still challenging and especially due to the difficulties to overcome the well-known problem of spin contamination. Here, we present a new and general method to compute magnetic exchange couplings in systems featuring several spin sites. To provide a consistent spin decontamination of J values, our strategy exploits the decomposition method of the magnetic exchange coupling proposed by Coulaud et al. and generalizes our previous work on diradical compounds where the overall magnetic exchange coupling is defined as the sum of its three main and properly extracted physical contributions (direct exchange, kinetic exchange, and spin polarization). In this aim, the generalized extraction of all contributions is presented to systems with multiple spin sites bearing one unpaired electron. This is done by proposing a new paradigm to treat the kinetic exchange contribution, which proceeds through monorelaxations of the magnetic orbitals. This method, so-called the recomposition method, is applied to a compound featuring three Cu(II) ions with a linear arrangement and to a recently synthesized complex containing a Cu4O4 cubane unit presenting an unusual magnetic behavior.
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Affiliation(s)
- Grégoire David
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes)-UMR 6226, F-35000Rennes, France
| | - Nicolas Ferré
- Aix-Marseille Univ, CNRS, ICR, 13013Marseille, France
| | - Boris Le Guennic
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes)-UMR 6226, F-35000Rennes, France
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6
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Aebersold LE, Hale AR, Christou G, Peralta JE. Validation of the Green's Function Approximation for the Calculation of Magnetic Exchange Couplings. J Phys Chem A 2022; 126:6790-6800. [PMID: 36129336 DOI: 10.1021/acs.jpca.2c05173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this work, we assess the potential of the Green's function approximation to predict isotropic magnetic exchange couplings and to reproduce the standard broken-symmetry energy difference approach for transition metal complexes. To this end, we have selected a variety of heterodinuclear, homodinuclear, and polynuclear systems containing 3d transition metal centers and computed the couplings using both the Green's function and energy difference methods. The Green's function approach is shown to have mixed results for the cases tested. For dinuclear complexes with large strength couplings (≳50 cm-1), the Green's function method is unable to reliably reproduce the energy difference values. However, for weaker dinuclear couplings, the Green's function approach acceptably reproduces broken-symmetry energy difference couplings. In polynuclear cases, the Green's function approximation worked remarkably well, especially for FeIII complexes. On the other hand, for a NiII polynuclear complex, qualitatively wrong couplings are predicted. Overall, the evaluation of exchange couplings from local rigid magnetization rotations offers a powerful alternative to time-consuming energy differences methods for large polynuclear transition metal complexes, but to achieve a quantitative agreement, some improvements to the method are needed.
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Affiliation(s)
- Lucas E Aebersold
- Department of Physics and Science of Advanced Materials, Central Michigan University, Mount Pleasant, Michigan 48859, United States
| | - Ashlyn R Hale
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| | - George Christou
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Juan E Peralta
- Department of Physics and Science of Advanced Materials, Central Michigan University, Mount Pleasant, Michigan 48859, United States
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7
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Sandoval-Olivares Z, Solis-Céspedes E, Páez-Hernández D. Antiferromagnetic Coupling Supported by Metallophilic Interactions: Theoretical View. Inorg Chem 2022; 61:1401-1417. [PMID: 35007080 DOI: 10.1021/acs.inorgchem.1c03068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The antiferromagnetic coupling supported by metallophilic interactions has been studied in the framework of the broken symmetry approach (BS) and multiconfigurational calculations (CASSCF). A series of heterobimetallic complexes of the form [PtCo(X)4(Y)]2 (X = tba thiobenzoate, SAc thioacetate, and Y = H2O, NO2py, py), previously reported, have been used as model systems. Magnetic coupling constants were found in good agreement with the experimental reports, and it could be concluded that axial ligands with a pure σ-donor character have a marked effect on the J value strengthening the antiferromagnetic coupling, as shown for [PtCo(SAc)4(H2O)]2 and [PtNi(SAc)4(H2O)]2. The latter complex, included for comparative purposes, also made it possible to evidence that the interaction between magnetic orbitals and low-level excitation in the Pt···Pt region is also relevant favoring the stronger antiferromagnetic coupling found in this case. A careful analysis of the energetic components involved in Pt···Pt interaction suggests that the stabilization arises from a combination of favorable orbital contributions, which allows a weak covalent Pt···Pt σ(dz2...dz2) bond. Theoretical tools evidence that the weak σ-bond found between monomeric units is responsible for a spin polarization mechanism resulting in the observed antiferromagnetic interaction. Multiconfigurational calculations finally allowed us to establish that the spin polarization mechanism involves not only the dz2 orbitals in the M-Pt···Pt-M bond direction but also the empty 6pz orbitals of Pt atoms. The inclusion of these orbitals favors a correlation-induced delocalization of magnetic orbitals and therefore a better balance among direct and kinetic exchange. The results shown in this work are relevant in the molecular design of systems supported by metallophilic interactions not only between platinum atoms but also could be extended to other cases with similar interactions.
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Affiliation(s)
- Zoraida Sandoval-Olivares
- Doctorado en Fisicoquímica Molecular, Universidad Andrés Bello, República 275, Santiago 8370146, Chile
| | - Eduardo Solis-Céspedes
- Escuela de Bioingeniería Médica, Facultad de Medicina, Universidad Católica del Maule, Maule 3460000, Chile.,Laboratorio de Bioinformática y Química Computacional, Facultad de Medicina, Universidad Católica del Maule, Maule 3460000, Chile
| | - Dayán Páez-Hernández
- Center of Applied Nanoscience (CANS), Universidad Andres Bello, República 330, Santiago 8370146, Chile.,Departamento de Ciencias Químicas, Universidad Andres Bello, República 275, Santiago 8370146, Chile
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8
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Rask AE, Zimmerman PM. Toward Full Configuration Interaction for Transition-Metal Complexes. J Phys Chem A 2021; 125:1598-1609. [DOI: 10.1021/acs.jpca.0c07624] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Alan E. Rask
- Department of Chemistry, University of Michigan, 930N. University Avenue, Ann Arbor 48109, Michigan, United States
| | - Paul M. Zimmerman
- Department of Chemistry, University of Michigan, 930N. University Avenue, Ann Arbor 48109, Michigan, United States
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9
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Horbatenko Y, Sadiq S, Lee S, Filatov M, Choi CH. Mixed-Reference Spin-Flip Time-Dependent Density Functional Theory (MRSF-TDDFT) as a Simple yet Accurate Method for Diradicals and Diradicaloids. J Chem Theory Comput 2021; 17:848-859. [PMID: 33401894 DOI: 10.1021/acs.jctc.0c01074] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Due to their multiconfigurational nature featuring strong electron correlation, accurate description of diradicals and diradicaloids is a challenge for quantum chemical methods. The recently developed mixed-reference spin-flip (MRSF)-TDDFT method is capable of describing the multiconfigurational electronic states of these systems while avoiding the spin-contamination pitfalls of SF-TDDFT. Here, we apply MRSF-TDDFT to study the adiabatic singlet-triplet (ST) gaps in a series of well-known diradicals and diradicaloids. On average, MRSF displays a very high prediction accuracy of the adiabatic ST gaps with the mean absolute error (MAE) amounting to 0.14 eV. In addition, MRSF is capable of accurately describing the effect of the Jahn-Teller distortion occurring in the trimethylenemethane diradical, the violation of the Hund rule in a series of the didehydrotoluene diradicals, and the potential energy surfaces of the didehydrobenzene (benzyne) diradicals. A convenient criterion for distinguishing diradicals and diradicaloids is suggested on the basis of the easily obtainable quantities. In all of these cases, which are difficult for the conventional methods of density functional theory (DFT), MRSF shows results consistent with the experiment and the high-level ab initio computations. Hence, the present study documents the reliability and accuracy of MRSF and lays out the guidelines for its application to strongly correlated molecular systems.
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Affiliation(s)
- Yevhen Horbatenko
- Department of Chemistry, Kyungpook National University, Daegu 702-701, South Korea
| | - Saima Sadiq
- Department of Chemistry, Kyungpook National University, Daegu 702-701, South Korea
| | - Seunghoon Lee
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Michael Filatov
- Department of Chemistry, Kyungpook National University, Daegu 702-701, South Korea
| | - Cheol Ho Choi
- Department of Chemistry, Kyungpook National University, Daegu 702-701, South Korea
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10
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Zhang D, Truhlar DG. Spin Splitting Energy of Transition Metals: A New, More Affordable Wave Function Benchmark Method and Its Use to Test Density Functional Theory. J Chem Theory Comput 2020; 16:4416-4428. [PMID: 32525690 DOI: 10.1021/acs.jctc.0c00518] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Accurately predicting the spin splitting energy of chemical species is important for understanding their reactivity and magnetic properties, but it is very challenging, especially for molecules containing transition metals. One impediment to progress is the scarcity of accurate benchmark data. Here we report a set of calculations designed to yield reliable benchmarks for simple transition-metal complexes that can be used to test density functional methods that are affordable for large systems of more practical interest. Various wave function methods are tested against experiment for Fe2+, Fe3+, and Co3+, including CASSCF, CASPT2, CASPT3, MRCISD, MRCISD+Q, ACPF, AQCC, CCSD(T), and CASPT2/CCSD(T) and also a new method called CASPT2.5, which is performed by taking the average of the CASPT2 and CASPT3 energies. We find that MRCISD+Q, ACPF, and AQCC require smaller active spaces for good accuracy than are required by CASPT2 and CASPT3, and this aspect may be important for calculations on larger molecules; here we find that CASPT2.5 extrapolated to a complete basis set is the most suitable method-in terms of computational cost and in terms of accuracy on monatomic systems-and therefore we chose this method for molecular benchmarks. Then Kohn-Sham density functional calculations with 60 exchange-correlation functionals are tested for FeF2, FeCl2, and CoF2. We find that MN15-L, M06-SX, and revM06 have very good agreement with CASPT2.5 benchmarks in terms of both the spin splitting energy and the optimized geometry for each spin state. In addition, we recommend def2-TZVP as the most suitable basis set to perform density functional calculations for molecular spin splitting energies; extra polarization functions in the basis set do not help to increase the accuracy of the spin splitting energy in KS calculations.
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Affiliation(s)
- Dayou Zhang
- Department of Chemistry, Chemical Theory Center, and Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
| | - Donald G Truhlar
- Department of Chemistry, Chemical Theory Center, and Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
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11
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Abstract
This Perspective discusses salient features of the spin-flip approach to strong correlation and describes different methods that sprung from this idea. The spin-flip treatment exploits the different physics of low-spin and high-spin states and is based on the observation that correlation is small for same-spin electrons. By using a well-behaved high-spin state as a reference, one can access problematic low-spin states by deploying the same formal tools as in the excited-state treatments (i.e., linear response, propagator, or equation-of-motion theories). The Perspective reviews applications of this strategy within wave function and density functional theory frameworks as well as the extensions for molecular properties and spectroscopy. The utility of spin-flip methods is illustrated by examples. Limitations and proposed future directions are also discussed.
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Affiliation(s)
- David Casanova
- Donostia International Physics Center (DIPC), 20018 Donostia, Euskadi, Spain. and IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Euskadi, Spain
| | - Anna I Krylov
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
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12
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Pantazis DA. Meeting the Challenge of Magnetic Coupling in a Triply-Bridged Chromium Dimer: Complementary Broken-Symmetry Density Functional Theory and Multireference Density Matrix Renormalization Group Perspectives. J Chem Theory Comput 2019; 15:938-948. [PMID: 30645093 PMCID: PMC6728064 DOI: 10.1021/acs.jctc.8b00969] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
![]()
Face-sharing
octahedral dinuclear Cr(III) compounds with d3–d3 electronic configurations represent nontrivial examples of
electronic complexity, posing particular challenges for theoretical
and computational studies. A tris-hydroxy-bridged Cr(III)–Cr(III)
system has proven to be a richly rewarding target for studies of magnetism
and electron paramagnetic resonance spectroscopy. It was also reported
to be a peculiarly difficult system to treat with density functional
theory (DFT). In this work the magnetic coupling problem for this
dimer is approached with broken-symmetry (BS)-DFT and multireference
calculations that utilize the density matrix renormalization group
(DMRG) to handle full-valence active spaces. BS-DFT is shown to recover
the correct ordering and energy spacing of Heisenberg spin states
if used in conjunction with appropriate spin projection procedures,
albeit with pronounced functional sensitivity. The contrasting conclusions
of previous studies are traced to incorrect inclusion of electronically
excited configurations. Analysis of the direct and differential overlap
of corresponding orbital pairs from the BS-DFT solution indicates
that metal–metal through-space interaction is the dominant
contributor to antiferromagnetic coupling. At the DFT level a procedure
that utilizes pseudopotential substitution is demonstrated that allows
evaluation of the direct exchange vs superexchange contributions.
A complementary description is obtained with DMRG-SCF calculations
that enable state-averaged CASSCF calculations with both metal and
bridge orbitals in the active space. A localized orbital subspace
analysis supports the DFT conclusions that in contrast to doubly bridged
isoelectronic analogues, antiferromagnetic coupling in the chromium
dimer arises primarily from direct metal–metal interaction
but is significantly enhanced by ligand-mediated superexchange.
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Affiliation(s)
- Dimitrios A Pantazis
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1 , 45470 Mülheim an der Ruhr , Germany
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13
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Saito T, Fujiwara M, Takano Y. Quantitative Assessment of rPM6 for Fluorine- and Chlorine-Containing Metal Complexes: Comparison with Experimental, First-Principles, and Other Semiempirical Results. Molecules 2018; 23:E3332. [PMID: 30558286 PMCID: PMC6321459 DOI: 10.3390/molecules23123332] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 12/12/2018] [Accepted: 12/14/2018] [Indexed: 11/17/2022] Open
Abstract
We report a reparameterization of PM6 parameters for fluorine and chlorine using our training set containing transition metal complexes. Spin unrestricted calculations with the resulting rPM6 (UrPM6) were examined quantitatively using two test sets: (i) the description of magnetic interactions in 25 dinuclear metal complexes and (ii) the prediction of barrier heights and reaction energies for epoxidation and fluorination reactions catalyzed by high-valent manganese-oxo species. The conventional UPM6 and UPM7 methods were also evaluated for comparison on the basis of either experimental or computational (the UB3LYP/SVP level) outcomes. The merits of UrPM6 are highlighted by both the test sets. As regards magnetic exchange coupling constants, the UrPM6 method had the smallest mean absolute errors from the experimental data (19 cm-1), followed by UPM7 (119 cm-1) and UPM6 (373 cm-1). For the epoxidation and fluorination reactions, all of the transition state searches were successful using UrPM6, while the success rates obtained by UPM6 and UPM7 were only 50%. The UrPM6-optimized stationary points also agreed well with the reference UB3LYP-optimized geometries. The accuracy for estimating reaction energies was also greatly remedied.
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Affiliation(s)
- Toru Saito
- Graduate School of Information Sciences, Hiroshima City University, 3-4-1 Ozuka-Higashi, Asa-Minami-Ku, Hiroshima 731-3194, Japan.
| | - Manami Fujiwara
- Graduate School of Information Sciences, Hiroshima City University, 3-4-1 Ozuka-Higashi, Asa-Minami-Ku, Hiroshima 731-3194, Japan.
| | - Yu Takano
- Graduate School of Information Sciences, Hiroshima City University, 3-4-1 Ozuka-Higashi, Asa-Minami-Ku, Hiroshima 731-3194, Japan.
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14
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Joshi RP, Trepte K, Withanage KPK, Sharkas K, Yamamoto Y, Basurto L, Zope RR, Baruah T, Jackson KA, Peralta JE. Fermi-Löwdin orbital self-interaction correction to magnetic exchange couplings. J Chem Phys 2018; 149:164101. [PMID: 30384709 DOI: 10.1063/1.5050809] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
We analyze the effect of removing self-interaction error on magnetic exchange couplings using the Fermi-Löwdin orbital self-interaction correction (FLOSIC) method in the framework of density functional theory (DFT). We compare magnetic exchange couplings obtained from self-interaction-free FLOSIC calculations with the local spin density approximation (LSDA) with several widely used DFT realizations and wave function based methods. To this end, we employ the linear H-He-H model system, six organic radical molecules, and [Cu2Cl6]2- as representatives of different types of magnetic interactions. We show that the simple self-interaction-free version of LSDA improves calculated couplings with respect to LSDA in all cases, even though the nature of the exchange interaction varies across the test set, and in most cases, it yields results comparable to modern hybrids and range-separated approximate functionals.
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Affiliation(s)
- Rajendra P Joshi
- Department of Physics, Science of Advanced Materials, Central Michigan University, Mount Pleasant, Michigan 48859, USA
| | - Kai Trepte
- Department of Physics, Central Michigan University, Mount Pleasant, Michigan 48859, USA
| | - Kushantha P K Withanage
- Department of Physics, Science of Advanced Materials, Central Michigan University, Mount Pleasant, Michigan 48859, USA
| | - Kamal Sharkas
- Department of Physics, Central Michigan University, Mount Pleasant, Michigan 48859, USA
| | - Yoh Yamamoto
- Department of Physics, University of Texas El Paso, El Paso, Texas 79968, USA
| | - Luis Basurto
- Department of Physics, University of Texas El Paso, El Paso, Texas 79968, USA
| | - Rajendra R Zope
- Department of Physics, University of Texas El Paso, El Paso, Texas 79968, USA
| | - Tunna Baruah
- Department of Physics, University of Texas El Paso, El Paso, Texas 79968, USA
| | - Koblar A Jackson
- Department of Physics, Science of Advanced Materials, Central Michigan University, Mount Pleasant, Michigan 48859, USA
| | - Juan E Peralta
- Department of Physics, Science of Advanced Materials, Central Michigan University, Mount Pleasant, Michigan 48859, USA
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15
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David G, Wennmohs F, Neese F, Ferré N. Chemical Tuning of Magnetic Exchange Couplings Using Broken-Symmetry Density Functional Theory. Inorg Chem 2018; 57:12769-12776. [DOI: 10.1021/acs.inorgchem.8b01970] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Frank Wennmohs
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr, 45470 North Rhine-Westphalia, Germany
| | - Frank Neese
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr, 45470 North Rhine-Westphalia, Germany
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16
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Orms N, Krylov AI. Singlet-triplet energy gaps and the degree of diradical character in binuclear copper molecular magnets characterized by spin-flip density functional theory. Phys Chem Chem Phys 2018; 20:13127-13144. [PMID: 29376159 DOI: 10.1039/c7cp07356a] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Molecular magnets, defined here as organic polyradicals, can be used as building blocks in the fabrication of novel and structurally diverse magnetic light-weight materials. We present a theoretical investigation of the lowest spin states of several binuclear copper diradicals. In contrast to previous studies, we consider not only the energetics of the low-lying states (which are related to the exchange-coupling parameter within the Heisenberg-Dirac-van-Vleck model), but also the character of the diradical states themselves. We use natural orbitals, their occupations, and the number of effectively unpaired electrons to quantify bonding patterns in these systems. We compare the performance of spin-flip time-dependent density functional theory (SF-TDDFT) using various functionals and effective core potentials against the wave function based approach, equation-of-motion spin-flip coupled-cluster method with single and double substitutions (EOM-SF-CCSD). We find that SF-TDDFT paired with the PBE50 and B5050LYP functionals performs comparably to EOM-SF-CCSD, with respect to both singlet-triplet gaps and states' characters. Visualization of frontier natural orbitals shows that the unpaired electrons are localized on copper centers, in some cases exhibiting slight through-bond interaction via copper d-orbitals and p-orbitals of neighboring ligand atoms. The analysis reveals considerable interactions between the formally unpaired electrons in the antiferromagnetic diradicaloids, meaning that they are poorly described by the Heisenberg-Dirac-van-Vleck model. Thus, for these systems the experimentally derived exchange-coupling parameters are not directly comparable with the singlet-triplet gaps. This explains systematic discrepancies between the computed singlet-triplet energy gaps and the exchange-coupling parameters extracted from experiment.
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Affiliation(s)
- Natalie Orms
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, USA.
| | - Anna I Krylov
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, USA.
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17
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Roemelt M, Krewald V, Pantazis DA. Exchange Coupling Interactions from the Density Matrix Renormalization Group and N-Electron Valence Perturbation Theory: Application to a Biomimetic Mixed-Valence Manganese Complex. J Chem Theory Comput 2017; 14:166-179. [PMID: 29211960 DOI: 10.1021/acs.jctc.7b01035] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The accurate description of magnetic level energetics in oligonuclear exchange-coupled transition-metal complexes remains a formidable challenge for quantum chemistry. The density matrix renormalization group (DMRG) brings such systems for the first time easily within reach of multireference wave function methods by enabling the use of unprecedentedly large active spaces. But does this guarantee systematic improvement in predictive ability and, if so, under which conditions? We identify operational parameters in the use of DMRG using as a test system an experimentally characterized mixed-valence bis-μ-oxo/μ-acetato Mn(III,IV) dimer, a model for the oxygen-evolving complex of photosystem II. A complete active space of all metal 3d and bridge 2p orbitals proved to be the smallest meaningful starting point; this is readily accessible with DMRG and greatly improves on the unrealistic metal-only configuration interaction or complete active space self-consistent field (CASSCF) values. Orbital optimization is critical for stabilizing the antiferromagnetic state, while a state-averaged approach over all spin states involved is required to avoid artificial deviations from isotropic behavior that are associated with state-specific calculations. Selective inclusion of localized orbital subspaces enables probing the relative contributions of different ligands and distinct superexchange pathways. Overall, however, full-valence DMRG-CASSCF calculations fall short of providing a quantitative description of the exchange coupling owing to insufficient recovery of dynamic correlation. Quantitatively accurate results can be achieved through a DMRG implementation of second order N-electron valence perturbation theory (NEVPT2) in conjunction with a full-valence metal and ligand active space. Perspectives for future applications of DMRG-CASSCF/NEVPT2 to exchange coupling in oligonuclear clusters are discussed.
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Affiliation(s)
- Michael Roemelt
- Lehrstuhl für Theoretische Chemie, Ruhr-University Bochum , 44780 Bochum, Germany.,Max Planck Institute for Coal Research, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Vera Krewald
- Department of Chemistry, University of Bath , Bath BA2 7AY, United Kingdom
| | - Dimitrios A Pantazis
- Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
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18
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David G, Guihéry N, Ferré N. What Are the Physical Contents of Hubbard and Heisenberg Hamiltonian Interactions Extracted from Broken Symmetry DFT Calculations in Magnetic Compounds? J Chem Theory Comput 2017; 13:6253-6265. [DOI: 10.1021/acs.jctc.7b00976] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Nathalie Guihéry
- LCPQ,
IRSAMC, Université de Toulouse 3, Paul Sabatier, 31400 Toulouse, France
| | - Nicolas Ferré
- Aix Marseille
Univ, CNRS, ICR, 13397 Marseille, France
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19
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Gupta P, Diefenbach M, Holthausen MC, Förster M. Copper-Mediated Selective Hydroxylation of a Non-activated C−H Bond in Steroids: A DFT Study of Schönecker's Reaction. Chemistry 2016; 23:1427-1435. [DOI: 10.1002/chem.201604829] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Puneet Gupta
- Institut für Anorganische und Analytische Chemie; Johann Wolfgang Goethe-Universität Frankfurt; Max-von-Laue-Straße 7 60438 Frankfurt am Main Germany
- Present address: Max-Planck-Institut für Kohlenforschung; Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
| | - Martin Diefenbach
- Institut für Anorganische und Analytische Chemie; Johann Wolfgang Goethe-Universität Frankfurt; Max-von-Laue-Straße 7 60438 Frankfurt am Main Germany
| | - Max C. Holthausen
- Institut für Anorganische und Analytische Chemie; Johann Wolfgang Goethe-Universität Frankfurt; Max-von-Laue-Straße 7 60438 Frankfurt am Main Germany
| | - Moritz Förster
- Institut für Anorganische und Analytische Chemie; Johann Wolfgang Goethe-Universität Frankfurt; Max-von-Laue-Straße 7 60438 Frankfurt am Main Germany
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20
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Reta Mañeru D, Moreira IDPR, Illas F. Helical Folding-Induced Stabilization of Ferromagnetic Polyradicals Based on Triarylmethyl Radical Derivatives. J Am Chem Soc 2016; 138:5271-5. [PMID: 27046281 DOI: 10.1021/jacs.5b11739] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Magnetic ordering in purely organic π-conjugated materials is a challenging, rare, and desirable event. The interest lies on the unique magnetic properties derived from high-spin carbon-based polymers/macromolecules tailored through appropriate synthetic routes. Ground-breaking achievements have been reported regarding magnetic ordering in an organic polymer using spin clusters as building blocks. This strategy leads to two-dimensional extended polyradicals with a concomitant loss of appealing macroscopic properties such as expected magnetic anisotropy in elongated shaped macromolecules containing carbon-bearing radicals. Here we provide compelling evidence of a secondary structure-induced stabilization of ferromagnetic polyradicals with robust magnetic properties and strongly suggest revisiting a discarded attempt to obtain polymeric linear-like radicals. An alternative synthetic approach is also proposed, based on polyradicals obtained from discrete molecular precursors (oligomers) long enough to ensure a secondary structure, rather than from polymerization processes.
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Affiliation(s)
- Daniel Reta Mañeru
- Departament de Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona , C/Martí i Franquès 1, 08028 Barcelona, Spain
| | - Ibério de P R Moreira
- Departament de Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona , C/Martí i Franquès 1, 08028 Barcelona, Spain
| | - Francesc Illas
- Departament de Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona , C/Martí i Franquès 1, 08028 Barcelona, Spain
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21
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Costa R, Valero R, Mañeru DR, Moreira IDPR, Illas F. Spin Adapted versus Broken Symmetry Approaches in the Description of Magnetic Coupling in Heterodinuclear Complexes. J Chem Theory Comput 2015; 11:1006-19. [DOI: 10.1021/ct5011483] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
| | - Rosendo Valero
- Center
for Superfunctional Materials, Department of Chemistry, School of
Natural Science, Ulsan National Institute of Science and Technology (UNIST), UNIST-gil 50, Ulsan 689-798, Korea
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22
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23
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Mayhall NJ, Head-Gordon M. Computational quantum chemistry for single Heisenberg spin couplings made simple: Just one spin flip required. J Chem Phys 2014; 141:134111. [DOI: 10.1063/1.4896659] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Affiliation(s)
- Nicholas J. Mayhall
- Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Martin Head-Gordon
- Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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24
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Casanova D. Second-order perturbative corrections to the restricted active space configuration interaction with the hole and particle approach. J Chem Phys 2014; 140:144111. [DOI: 10.1063/1.4870638] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
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25
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Phillips JJ, Peralta JE. Magnetic Exchange Couplings from Noncollinear Perturbation Theory: Dinuclear CuII Complexes. J Phys Chem A 2014; 118:5841-7. [DOI: 10.1021/jp411577a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jordan J. Phillips
- Science
of Advanced Materials, Central Michigan University, Mt. Pleasant, Michigan 48859, United States
| | - Juan E. Peralta
- Science
of Advanced Materials, Central Michigan University, Mt. Pleasant, Michigan 48859, United States
- Department
of Physics, Central Michigan University, Mt. Pleasant, Michigan 48859, United States
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26
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Reta Mañeru D, Pal AK, Moreira IDPR, Datta SN, Illas F. The Triplet–Singlet Gap in the m-Xylylene Radical: A Not So Simple One. J Chem Theory Comput 2013; 10:335-45. [DOI: 10.1021/ct400883m] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Daniel Reta Mañeru
- Departament de Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, C/Martí i Franquès 1, E-08028 Barcelona, Spain
| | - Arun K. Pal
- Department
of Chemistry, Indian Institute of Technology, Bombay, Powai, Mumbai 400076, India
| | - Ibério de P. R. Moreira
- Departament de Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, C/Martí i Franquès 1, E-08028 Barcelona, Spain
| | - Sambhu N. Datta
- Department
of Chemistry, Indian Institute of Technology, Bombay, Powai, Mumbai 400076, India
| | - Francesc Illas
- Departament de Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, C/Martí i Franquès 1, E-08028 Barcelona, Spain
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27
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Milko P, Iron MA. On the Innocence of Bipyridine Ligands: How Well Do DFT Functionals Fare for These Challenging Spin Systems? J Chem Theory Comput 2013; 10:220-35. [DOI: 10.1021/ct400913z] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Petr Milko
- Computational
Chemistry Unit,
Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel 76100
| | - Mark A. Iron
- Computational
Chemistry Unit,
Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel 76100
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28
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Phillips JJ, Peralta JE, Christou G. Magnetic Couplings in Spin Frustrated Fe7III Disklike Clusters. J Chem Theory Comput 2013; 9:5585-9. [DOI: 10.1021/ct4007376] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jordan J. Phillips
- Science
of Advanced Materials, Central Michigan University, Mt. Pleasant, Michigan 48859, United States
| | - Juan E. Peralta
- Science
of Advanced Materials, Central Michigan University, Mt. Pleasant, Michigan 48859, United States
- Department of Physics, Central Michigan University, Mt.
Pleasant, Michigan 48859, United States
| | - George Christou
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
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29
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Malrieu JP, Caballol R, Calzado CJ, de Graaf C, Guihéry N. Magnetic interactions in molecules and highly correlated materials: physical content, analytical derivation, and rigorous extraction of magnetic Hamiltonians. Chem Rev 2013; 114:429-92. [PMID: 24102410 DOI: 10.1021/cr300500z] [Citation(s) in RCA: 282] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Jean Paul Malrieu
- Laboratoire de Chimie et Physique Quantiques, Université de Toulouse 3 , 118 route de Narbonne, 31062 Toulouse, France
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30
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Isegawa M, Truhlar DG. Valence excitation energies of alkenes, carbonyl compounds, and azabenzenes by time-dependent density functional theory: linear response of the ground state compared to collinear and noncollinear spin-flip TDDFT with the Tamm-Dancoff approximation. J Chem Phys 2013; 138:134111. [PMID: 23574212 DOI: 10.1063/1.4798402] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Time-dependent density functional theory (TDDFT) holds great promise for studying photochemistry because of its affordable cost for large systems and for repeated calculations as required for direct dynamics. The chief obstacle is uncertain accuracy. There have been many validation studies, but there are also many formulations, and there have been few studies where several formulations were applied systematically to the same problems. Another issue, when TDDFT is applied with only a single exchange-correlation functional, is that errors in the functional may mask successes or failures of the formulation. Here, to try to sort out some of the issues, we apply eight formulations of adiabatic TDDFT to the first valence excitations of ten molecules with 18 density functionals of diverse types. The formulations examined are linear response from the ground state (LR-TDDFT), linear response from the ground state with the Tamm-Dancoff approximation (TDDFT-TDA), the original collinear spin-flip approximation with the Tamm-Dancoff (TD) approximation (SF1-TDDFT-TDA), the original noncollinear spin-flip approximation with the TDA approximation (SF1-NC-TDDFT-TDA), combined self-consistent-field (SCF) and collinear spin-flip calculations in the original spin-projected form (SF2-TDDFT-TDA) or non-spin-projected (NSF2-TDDFT-TDA), and combined SCF and noncollinear spin-flip calculations (SF2-NC-TDDFT-TDA and NSF2-NC-TDDFT-TDA). Comparing LR-TDDFT to TDDFT-TDA, we observed that the excitation energy is raised by the TDA; this brings the excitation energies underestimated by full linear response closer to experiment, but sometimes it makes the results worse. For ethylene and butadiene, the excitation energies are underestimated by LR-TDDFT, and the error becomes smaller making the TDA. Neither SF1-TDDFT-TDA nor SF2-TDDFT-TDA provides a lower mean unsigned error than LR-TDDFT or TDDFT-TDA. The comparison between collinear and noncollinear kernels shows that the noncollinear kernel drastically reduces the spin contamination in the systems considered here, and it makes the results more accurate than collinear spin-flip TDDFT for functionals with a low percentage of Hartree-Fock exchange and sometimes for functionals with a higher percentage of Hartree-Fock exchange, but it yields less accurate results than ground-state TDDFT.
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Affiliation(s)
- Miho Isegawa
- Department of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, USA
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31
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Phillips JJ, Peralta JE. Towards the blackbox computation of magnetic exchange coupling parameters in polynuclear transition-metal complexes: Theory, implementation, and application. J Chem Phys 2013; 138:174115. [DOI: 10.1063/1.4802776] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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32
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Polynuclear complexes of a new macrocyclic oxamide metalloligand: Syntheses, crystal structures and deoxyribonucleic acid cleavage and magnetic properties. Inorganica Chim Acta 2013. [DOI: 10.1016/j.ica.2012.11.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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33
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Maurice R, Graaf CD, Guihéry N. Theoretical determination of spin Hamiltonians with isotropic and anisotropic magnetic interactions in transition metal and lanthanide complexes. Phys Chem Chem Phys 2013; 15:18784-804. [DOI: 10.1039/c3cp52521j] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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34
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Wannarit N, Pakawatchai C, Mutikainen I, Costa R, Moreira IDPR, Youngme S, Illas F. Hetero triply-bridged dinuclear copper(ii) compounds with ferromagnetic coupling: a challenge for current density functionals. Phys Chem Chem Phys 2013; 15:1966-75. [DOI: 10.1039/c2cp43839a] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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35
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Isegawa M, Peverati R, Truhlar DG. Performance of recent and high-performance approximate density functionals for time-dependent density functional theory calculations of valence and Rydberg electronic transition energies. J Chem Phys 2012; 137:244104. [DOI: 10.1063/1.4769078] [Citation(s) in RCA: 149] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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36
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Sousa C, Tosoni S, Illas F. Theoretical Approaches to Excited-State-Related Phenomena in Oxide Surfaces. Chem Rev 2012. [DOI: 10.1021/cr300228z] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Carmen Sousa
- Departament de Química
Física and Institut de Química Teòrica i Computacional
(IQTCUB), Universitat de Barcelona, C/Martí
i Franquès 1, 08028 Barcelona, Spain
| | - Sergio Tosoni
- Departament de Química
Física and Institut de Química Teòrica i Computacional
(IQTCUB), Universitat de Barcelona, C/Martí
i Franquès 1, 08028 Barcelona, Spain
- Departamento de Química, Universidad de Las Palmas de Gran Canaria, Campus Universitario
de Tafira, 35017 Las Palmas de Gran Canaria, Spain
| | - Francesc Illas
- Departament de Química
Física and Institut de Química Teòrica i Computacional
(IQTCUB), Universitat de Barcelona, C/Martí
i Franquès 1, 08028 Barcelona, Spain
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37
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Coulaud E, Guihéry N, Malrieu JP, Hagebaum-Reignier D, Siri D, Ferré N. Analysis of the physical contributions to magnetic couplings in broken symmetry density functional theory approach. J Chem Phys 2012; 137:114106. [DOI: 10.1063/1.4752412] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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38
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Phillips JJ, Peralta JE. Magnetic Exchange Couplings from Semilocal Functionals Evaluated Nonself-Consistently on Hybrid Densities: Insights on Relative Importance of Exchange, Correlation, and Delocalization. J Chem Theory Comput 2012; 8:3147-58. [DOI: 10.1021/ct3004904] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Jordan J. Phillips
- Science of Advanced Materials, Central Michigan University, Mt. Pleasant, Michigan
48859, United States
| | - Juan E. Peralta
- Department
of Physics, Central Michigan University, Mt. Pleasant, Michigan 48859, United States
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39
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Ali ME, Nair NN, Staemmler V, Marx D. Constrained spin-density dynamics of an iron-sulfur complex: Ferredoxin cofactor. J Chem Phys 2012; 136:224101. [DOI: 10.1063/1.4722552] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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40
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Fajín JLC, D. S. Cordeiro MN, Gomes JRB, Illas F. On the Need for Spin Polarization in Heterogeneously Catalyzed Reactions on Nonmagnetic Metallic Surfaces. J Chem Theory Comput 2012; 8:1737-43. [DOI: 10.1021/ct3001415] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- José L. C. Fajín
- REQUIMTE, Faculdade de Ciências, Universidade do Porto, P-4169-007, Porto, Portugal
| | | | - José R. B. Gomes
- CICECO, Departamento de Química, Universidade de Aveiro, 3810-193 Aveiro, Portugal
| | - Francesc Illas
- Department de Química Física & Institut de Química Teòrica i Computacional (IQTCUB), University of Barcelona, C/Martí i Franquès 1, 08028 Barcelona, Spain
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41
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Bandeira NAG, Guennic BL. Calculation of Magnetic Couplings in Hydrogen-Bonded Cu(II) Complexes Using Density Functional Theory. J Phys Chem A 2012; 116:3465-73. [DOI: 10.1021/jp300618v] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nuno A G Bandeira
- Université de Lyon, CNRS, Institut de Chimie de Lyon, Ecole Normale Supérieure de Lyon, France
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42
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Paul S, Misra A. Interpretation and Quantification of Magnetic Interaction through Spin Topology. J Chem Theory Comput 2012; 8:843-53. [PMID: 26593346 DOI: 10.1021/ct2006506] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Satadal Paul
- Department of Chemistry, University of North Bengal,
Siliguri, PIN 734 013, West Bengal, India
| | - Anirban Misra
- Department of Chemistry, University of North Bengal,
Siliguri, PIN 734 013, West Bengal, India
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