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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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Lobayan RM, Bochicchio RC, Marturet AD. Topological description of complex patterns of bonding, charge transference and structural changes in chemical reactions: SN2 type reactions, a case study. J Mol Graph Model 2022; 112:108121. [DOI: 10.1016/j.jmgm.2021.108121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 12/21/2021] [Accepted: 12/31/2021] [Indexed: 11/29/2022]
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3
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Misiewicz JP, Turney JM, Schaefer HF. Cumulants as the variables of density cumulant theory: A path to Hermitian triples. J Chem Phys 2021; 155:244105. [PMID: 34972366 DOI: 10.1063/5.0076888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We study the combination of orbital-optimized density cumulant theory and a new parameterization of reduced density matrices in which the variables are the particle-hole cumulant elements. We call this combination OλDCT. We find that this new Ansatz solves problems identified in the previous unitary coupled cluster Ansatz for density cumulant theory: the theory is now free of near-zero denominators between occupied and virtual blocks, can correctly describe the dissociation of H2, and is rigorously size-extensive. In addition, the new Ansatz has fewer terms than the previous unitary Ansatz, and the optimal orbitals delivered by the exact theory are the natural orbitals. Numerical studies on systems amenable to full configuration interaction show that the amplitudes from the previous ODC-12 method approximate the exact amplitudes predicted by this Ansatz. Studies on equilibrium properties of diatomic molecules show that even with the new Ansatz, it is necessary to include triples to improve the accuracy of the method compared to orbital-optimized linearized coupled cluster doubles. With a simple iterative triples correction, OλDCT outperforms other orbital-optimized methods truncated at comparable levels in the amplitudes, as well as coupled cluster single and doubles with perturbative triples [CCSD(T)]. By adding four more terms to the cumulant parameterization, OλDCT outperforms CCSDT while having the same O(V5O3) scaling.
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Affiliation(s)
- Jonathon P Misiewicz
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Justin M Turney
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Henry F Schaefer
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA
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Pokhilko P, Zgid D. Interpretation of multiple solutions in fully iterative GF2 and GW schemes using local analysis of two-particle density matrices. J Chem Phys 2021; 155:024101. [DOI: 10.1063/5.0055191] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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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Misiewicz JP, Turney JM, Schaefer HF, Sokolov AY. Assessing the orbital-optimized unitary Ansatz for density cumulant theory. J Chem Phys 2020; 153:244102. [PMID: 33380073 DOI: 10.1063/5.0036512] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The previously proposed Ansatz for density cumulant theory that combines orbital-optimization and a parameterization of the 2-electron reduced density matrix cumulant in terms of unitary coupled cluster amplitudes (OUDCT) is carefully examined. Formally, we elucidate the relationship between OUDCT and orbital-optimized unitary coupled cluster theory and show the existence of near-zero denominators in the stationarity conditions for both the exact and some approximate OUDCT methods. We implement methods of the OUDCT Ansatz restricted to double excitations for numerical study, up to the fifth commutator in the Baker-Campbell-Hausdorff expansion. We find that methods derived from the Ansatz beyond the previously known ODC-12 method tend to be less accurate for equilibrium properties and less reliable when attempting to describe H2 dissociation. New developments are needed to formulate more accurate density cumulant theory variants.
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Affiliation(s)
- Jonathon P Misiewicz
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Justin M Turney
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Henry F Schaefer
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Alexander Yu Sokolov
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
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Lobayan RM, Bochicchio RC, Pérez Del Valle C. Topological population analysis and pairing/unpairing electron distribution evolution: Atomic B3 + cluster bending mode, a case study. J Mol Graph Model 2020; 100:107696. [PMID: 32763795 DOI: 10.1016/j.jmgm.2020.107696] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/26/2020] [Accepted: 07/12/2020] [Indexed: 12/01/2022]
Abstract
Local and non-local topological treatment of electronic distributions are applied to a simple out of equilibrium case of an electron-deficient three-atom cluster, B3+. The bending movement is described in detail through the onset and disappearance of critical points defining two kinds of molecular structures, characterizing a transition state (TS) and predicting two stable equilibrium geometries. All points in this rich evolution and the structural change in the out of equilibrium conformations has been featured and distinguished by the behavior of the population magnitudes and of the paired and unpaired electron densities within the non-local and local points of view of the topological formalism. The unpaired or electron hole density appears as relevant in both versions, the non-local or integrated one, in which it is sometimes called free-valence and also for its complementary counterpart, the local one, to describe and to quantify the interatomic interactions. The stability of the cluster B3+ is characterized in terms of a topologically defined ring structure and the highest total two- and three-center populations, thus showing the role of the geometry, the covalence, and the complex patterns. Consideration of the electron correlation effects constitutes the basement of the results gathered, thus displaying their influence in the formation and breaking of boron bonding interactions.
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Affiliation(s)
- Rosana M Lobayan
- Departamento de Física, Facultad de Ciencias Exactas, Naturales y Agrimensura Universidad Nacional Del Nordeste, 3400, Corrientes, Argentina.
| | - Roberto C Bochicchio
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Ciudad Universitaria, 1428, Buenos Aires, Argentina
| | - Carlos Pérez Del Valle
- Institut de Sciences de la Terre and Département de Chimie Moléculaire, Université Grenoble Alpes, Grenoble Cedex, F-38000, Grenoble, France
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Lei Y, Zhu C, Lu J, Zhu Y, Zhang Q, Chen T, Xiong H. Photochemical oxidation of di-n-butyl phthalate in atmospheric hydrometeors by hydroxyl radicals from nitrous acid. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:31091-31100. [PMID: 30187409 DOI: 10.1007/s11356-018-3091-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 08/27/2018] [Indexed: 06/08/2023]
Abstract
The photochemical oxidation of di-n-butyl phthalate (DBP) by •OH radicals from nitrous acid (HONO) in atmospheric hydrometeors was explored by two techniques, steady-state irradiation, and laser flash photolysis (LFP). The effects of atmospheric liquid parameters on DBP transformation were systematically evaluated, showing that DBP does not react with HONO directly and •OH-initiated reactions are crucial steps for consumption and transformation of DBP. Two reaction channels are operative: •OH addition and hydrogen atom abstraction. The overall rate constant for the reaction of DBP with •OH is 5.7 × 109 M-1 s-1, and its specific rate constant for addition is 3.7 × 109 M-1 s-1 determined by using laser flash photolysis technique. Comparing the individual reaction rate constant for aromatic ring addition with the total rate constant, the majority of the •OH radicals (about 65%) attack the aromatic ring. The major transformation products were identified by GC-MS, and the trends of their yields derived from both ring addition and H-abstraction with time are discussed. These results provide important insights into the photochemical transformation of DBP in atmospheric hydrometeors and contribute to atmospheric aerosol chemistry.
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Affiliation(s)
- Yu Lei
- Institute of Atmospheric Environment and Pollution Control, School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, 230009, People's Republic of China
| | - Chengzhu Zhu
- Institute of Atmospheric Environment and Pollution Control, School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, 230009, People's Republic of China.
| | - Jun Lu
- Center of Analysis and Measurement, Hefei University of Technology, Hefei, 230009, People's Republic of China
| | - Yongchao Zhu
- Institute of Atmospheric Environment and Pollution Control, School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, 230009, People's Republic of China
| | - Qiuyue Zhang
- Institute of Atmospheric Environment and Pollution Control, School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, 230009, People's Republic of China
| | - Tianhu Chen
- Institute of Atmospheric Environment and Pollution Control, School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, 230009, People's Republic of China
| | - Hongbin Xiong
- Institute of Atmospheric Environment and Pollution Control, School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, 230009, People's Republic of China.
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Kyriakidou K, Karafiloglou P. Natural bond orbitals: Local sets showing minimal intra-pair correlations and minimal unpaired electron populations. COMPUT THEOR CHEM 2017. [DOI: 10.1016/j.comptc.2016.11.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Lobayan RM, Bochicchio RC. Do Organometallic CH4-Me(+p) Adducts and X4H(+) (X = P, As) Clusters Undergo Two-Electron Three-Center Interactions? Some Aspects of Discussion. J Phys Chem A 2015; 119:7000-12. [PMID: 26061421 DOI: 10.1021/acs.jpca.5b03267] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Most of the systems possessing true two-electron three-center interactions are electron deficient compounds like boron hydrids, closo-boranes, and some organic ions such as butonium cations. In this work, we perform a detailed study of the electron distribution for two different types of systems to which likewise interactions has been adjudicated: organometallic CH4-Me(+p) (p = 1, 2) adducts with Me, alkaline and earth alkaline metallic ions of Li, Na, K, Be, Mg, Ca in their stable gaseous phase and X4H(+) (X = P, As) simple clusters. For this purpose, topological analysis of the electron density decomposed into its effectively paired and unpaired contributions has been carried out looking for complex interactions.
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Affiliation(s)
- Rosana M Lobayan
- †Departamento de Física, Facultad de Ciencias Exactas, Naturales y Agrimensura, Universidad Nacional del Nordeste, 3400, Corrientes, Argentina
| | - Roberto C Bochicchio
- ‡IFIBA-CONICET and Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428, Buenos Aires, Argentina
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11
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Lobayan RM, Bochicchio RC. Pairing and unpairing electron densities in organic systems: two-electron three center through space and through bonds interactions. J Chem Phys 2014; 140:174302. [PMID: 24811636 DOI: 10.1063/1.4873547] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Two-electron three-center bonding interactions in organic ions like methonium (CH5(+)), ethonium (C2H7(+)), and protonated alkanes n - C4H11(+) isomers (butonium cations) are described and characterized within the theoretical framework of the topological analysis of the electron density decomposition into its effectively paired and unpaired contributions. These interactions manifest in some of this type of systems as a concentration of unpaired electron cloud around the bond paths, in contrast to the well known paradigmatic boron hydrids in which it is not only concentrated close to the atomic nucleus and the bond paths but out of them and over the region defined by the involved atoms as a whole. This result permits to propose an attempt of classification for these interactions based in such manifestations. In the first type, it is called as interactions through bonds and in the second type as interactions through space type.
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Affiliation(s)
- Rosana M Lobayan
- Departamento de Física, Facultad de Ciencias Exactas, Naturales y Agrimensura, Universidad Nacional del Nordeste, 3400, Corrientes, Argentina
| | - Roberto C Bochicchio
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, and IFIBA, CONICET, Ciudad Universitaria, 1428, Buenos Aires, Argentina
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Lobayan RM, Bochicchio RC. Pairing and unpairing electron densities in organic systems: [1.1.1]Propellane case. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2012.11.093] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Alcoba DR, Torre A, Lain L, Bochicchio RC. Determination of Local Spins by Means of a Spin-Free Treatment. J Chem Theory Comput 2011; 7:3560-6. [DOI: 10.1021/ct200594f] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Diego R. Alcoba
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and Instituto de Física de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, 1428, Buenos Aires, Argentina
| | - Alicia Torre
- Departamento de Química Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Apdo. 644 E-48080 Bilbao, Spain
| | - Luis Lain
- Departamento de Química Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Apdo. 644 E-48080 Bilbao, Spain
| | - Roberto C. Bochicchio
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and Instituto de Física de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, 1428, Buenos Aires, Argentina
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Lobayan RM, Bochicchio RC, Torre A, Lain L. Electronic Structure and Effectively Unpaired Electron Density Topology in closo-Boranes: Nonclassical Three-Center Two-Electron Bonding. J Chem Theory Comput 2011; 7:979-87. [DOI: 10.1021/ct100753q] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Rosana M. Lobayan
- Facultad de Ingeniería, Universidad de la Cuenca del Plata, Lavalle 50, 3400, Corrientes, Argentina
| | - Roberto C. Bochicchio
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, and Instituto de Física de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, 1428, Buenos Aires, Argentina
| | - Alicia Torre
- Departamento de Química Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Apartado 644, E-48080 Bilbao, Spain
| | - Luis Lain
- Departamento de Química Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Apartado 644, E-48080 Bilbao, Spain
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A study of the relationships between unpaired electron density, spin-density and cumulant matrices. Theor Chem Acc 2010. [DOI: 10.1007/s00214-010-0795-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Torre A, Alcoba DR, Lain L, Bochicchio RC. Relationships between Cumulant and Spin-Density Matrices: Application to the Decomposition of Spin. J Phys Chem A 2010; 114:2344-9. [DOI: 10.1021/jp9090848] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alicia Torre
- Departamento de Química Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Apdo. 644 E48080 Bilbao, Spain and Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428, Buenos Aires, Argentina
| | - Diego R. Alcoba
- Departamento de Química Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Apdo. 644 E48080 Bilbao, Spain and Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428, Buenos Aires, Argentina
| | - Luis Lain
- Departamento de Química Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Apdo. 644 E48080 Bilbao, Spain and Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428, Buenos Aires, Argentina
| | - Roberto C. Bochicchio
- Departamento de Química Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Apdo. 644 E48080 Bilbao, Spain and Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428, Buenos Aires, Argentina
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Nagashima K, Takatsuka K. Electron-Wavepacket Reaction Dynamics in Proton Transfer of Formamide. J Phys Chem A 2009; 113:15240-9. [DOI: 10.1021/jp905583s] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kengo Nagashima
- Department of Basic Science, Graduate School of Arts and Sciences, University of Tokyo, Komaba, 153-8902 Tokyo, Japan
| | - Kazuo Takatsuka
- Department of Basic Science, Graduate School of Arts and Sciences, University of Tokyo, Komaba, 153-8902 Tokyo, Japan
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Lobayan RM, Bochicchio RC, Torre A, Lain L. Topology of the Effectively Paired and Unpaired Electron Densities for Complex Bonding Patterns: The Three-Center Two-Electron Bonding Case. J Chem Theory Comput 2009; 5:2030-43. [DOI: 10.1021/ct900281q] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Rosana M. Lobayan
- Facultad de Ingeniería, Universidad de la Cuenca del Plata, Lavalle 50, 3400 Corrientes, Argentina, Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina, and Departamento de Química Física, Facultad de Ciencias, Universidad del País Vasco, Apdo, 644 E-48080 Bilbao, Spain
| | - Roberto C. Bochicchio
- Facultad de Ingeniería, Universidad de la Cuenca del Plata, Lavalle 50, 3400 Corrientes, Argentina, Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina, and Departamento de Química Física, Facultad de Ciencias, Universidad del País Vasco, Apdo, 644 E-48080 Bilbao, Spain
| | - Alicia Torre
- Facultad de Ingeniería, Universidad de la Cuenca del Plata, Lavalle 50, 3400 Corrientes, Argentina, Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina, and Departamento de Química Física, Facultad de Ciencias, Universidad del País Vasco, Apdo, 644 E-48080 Bilbao, Spain
| | - Luis Lain
- Facultad de Ingeniería, Universidad de la Cuenca del Plata, Lavalle 50, 3400 Corrientes, Argentina, Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina, and Departamento de Química Física, Facultad de Ciencias, Universidad del País Vasco, Apdo, 644 E-48080 Bilbao, Spain
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Karafiloglou P. An efficient generalized polyelectron population analysis in orbital spaces: the hole-expansion methodology. J Chem Phys 2009; 130:164103. [PMID: 19405557 DOI: 10.1063/1.3116083] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
We present relations leading to an efficient generalized population analysis in orbital spaces of usual delocalized molecular orbital wave functions. Besides the calculation of the diagonal elements of the reduced density matrices of any order, one can also calculate efficiently the probabilities (or, in general, the weights) of various occupation schemes of local electronic structures, by using generalized density operators referring to both electrons and electron holes. Within this population analysis, correlated molecular orbital wave functions can be used, and there are no restrictions to the number of the analyzed electrons and electron holes. It is based on the hole-expansion methodology, according to which a given electronic population is expanded in terms involving only electron holes, which as shown, can be calculated very efficiently; usual difficulties arising from the necessity to handle extremely large local determinantal basis sets are avoided, without introducing approximations. Although an emphasis is given for populations in the basis of orthogonal orbital spaces (providing probabilities), the case of nonorthogonal ones is also considered in order to show the connection of the generalized populations and the traditional weights obtained from valence-bond wave functions. Physically meaningful populations can be obtained by using natural orbitals, such as the natural atomic orbitals (NAOs) (orthogonal orbitals) or the pre-NAO's (nonorthogonal orbitals); numerical applications for pyrrole molecule are presented in the basis of these natural orbitals.
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Affiliation(s)
- P Karafiloglou
- Department of General and Inorganic Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, P.O. Box 135, 54124 Thessaloniki, Greece.
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Alcoba DR, Oña O, Torre A, Lain L, Bochicchio RC. Determination of Energies and Electronic Densities of Functional Groups According to Partitionings in the Physical Space. J Phys Chem A 2008; 112:10023-8. [DOI: 10.1021/jp804225x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Diego R. Alcoba
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428, Buenos Aires, Argentina, and Departamento de Química Física, Facultad de Ciencias, Universidad del País Vasco, Apdo. 644, E-48080, Bilbao, Spain
| | - Ofelia Oña
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428, Buenos Aires, Argentina, and Departamento de Química Física, Facultad de Ciencias, Universidad del País Vasco, Apdo. 644, E-48080, Bilbao, Spain
| | - Alicia Torre
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428, Buenos Aires, Argentina, and Departamento de Química Física, Facultad de Ciencias, Universidad del País Vasco, Apdo. 644, E-48080, Bilbao, Spain
| | - Luis Lain
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428, Buenos Aires, Argentina, and Departamento de Química Física, Facultad de Ciencias, Universidad del País Vasco, Apdo. 644, E-48080, Bilbao, Spain
| | - Roberto C. Bochicchio
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428, Buenos Aires, Argentina, and Departamento de Química Física, Facultad de Ciencias, Universidad del País Vasco, Apdo. 644, E-48080, Bilbao, Spain
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Alcoba DR, Torre A, Lain L, Bochicchio RC. Energy decompositions according to physical space partitioning schemes: Treatments of the density cumulant. J Chem Phys 2007; 127:104110. [PMID: 17867740 DOI: 10.1063/1.2772855] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
This article is a continuation of our previous paper on schemes of energy decompositions of molecular systems in the real space [D. R. Alcoba et al., J. Chem. Phys. 122, 074102 (2005)] now using correlated state functions. We study, according to physical arguments, the appropriate management of the density cumulant arising from the second-order reduced density matrix at correlated level, whose contributions can be assigned to one-center or to two-center terms in the energy partitioning. Our treatments are applied within two physical space partitioning schemes: the Bader partitioning into atomic basins and the fuzzy atom procedure. The results obtained in selected molecules are analyzed and discussed in detail.
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Affiliation(s)
- Diego R Alcoba
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina
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Karafiloglou P. Control of delocalization and structural changes by means of an electric field. J Comput Chem 2007; 27:1883-91. [PMID: 16983670 DOI: 10.1002/jcc.20509] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The strength and, mainly, the direction of a static electric field can be used to control delocalization effects occurring in a non-polar pi-system. The delocalization energy, the weights, and the probabilities of some local electronic structures, the behavior of electron pairs, and the electronic fluctuations are considered and examined in cis-butadiene, used as model system. The effects of the electric field are detected and evaluated in the basis of natural orbital spaces appropriate to investigate the behavior of one- and poly-electron distributions. The consequences of modifying the delocalization effects on structural changes are also investigated. Full geometry optimizations in both Hartree-Fock and MP2 levels show that the changes in bond lengths, guided by the changes of the behavior of the electronic assembly, can be controlled by means of the electric field.
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Affiliation(s)
- Padeleimon Karafiloglou
- Faculty of Chemistry, POB 135, Department of General and Inorganic Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
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Lobayan RM, Bochicchio RC, Lain L, Torre A. Laplacian Field of the Effectively Unpaired Electron Density: Determination of Many-Body Effects on Electron Distributions. J Phys Chem A 2007; 111:3166-72. [PMID: 17402714 DOI: 10.1021/jp0681101] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This work carries out the study of the Laplacian field function of the electron density L(r) = -nabla2rho(r) splitted in two contributions rho(r) = rho(p)(r) + rho(u)(r), which correspond to the effectively paired and effectively unpaired electron densities, respectively. The visualization of the concentration and depletion of these fields and their spatial localization show no contribution of the effectively unpaired electrons to the conventional bonding among two centers, but the field -nabla2rho(u)(r) provides an interesting structure. We also study the reliability of the information contained in the partitioning of this electron density field function for describing nonclassical bondings as the three-center two-electron ones.
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Affiliation(s)
- Rosana M Lobayan
- Facultad de Ingeniería, Universidad de la Cuenca del Plata, Lavalle 50, 3400 Corrientes, Argentina
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On the definition of the effectively unpaired electron density matrix: A similarity measure approach. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2006.07.068] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Alcoba DR, Lain L, Torre A, Bochicchio RC. Treatment of non-nuclear attractors within the theory of atoms in molecules II: Energy decompositions. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2006.05.065] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Alcoba DR, Lain L, Torre A, Bochicchio RC. A study of the partitioning of the first-order reduced density matrix according to the theory of atoms in molecules. J Chem Phys 2005; 123:144113. [PMID: 16238380 DOI: 10.1063/1.2069927] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
This work describes a simple spatial decomposition of the first-order reduced density matrix corresponding to an N-electron system into first-order density matrices, each of them associated to an atomic domain defined in the theory of atoms in molecules. A study of the representability of the density matrices arisen from this decomposition is reported and analyzed. An appropriate treatment of the eigenvectors of the matrices defined over atomic domains or over unions of these domains allows one to describe satisfactorily molecular properties and chemical bondings within a determined molecule and among its fragments. Numerical determinations, performed in selected molecules, confirm the reliability of our proposal.
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Affiliation(s)
- Diego R Alcoba
- Departamento de Química Física, Facultad de Ciencias, Universidad del País Vasco, Bilbao, Spain
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Ponec R, Cooper DL. Anatomy of bond formation. Bond length dependence of the extent of electron sharing in chemical bonds. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/j.theochem.2005.02.032] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Torre A, Alcoba DR, Lain L, Bochicchio RC. Determination of Three-Center Bond Indices from Population Analyses: A Fuzzy Atom Treatment. J Phys Chem A 2005; 109:6587-91. [PMID: 16834006 DOI: 10.1021/jp0520446] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This work proposes the use of the treatment referred to as fuzzy atoms to describe three-center bond indices within studies of electron population analysis. A simple manipulation of our algorithms reported previously for describing multicenter bondings enables us to introduce this methodology in our mathematical framework, providing suitable numerical determinations of three-center bond indices, two-center bond ones, and electron atomic populations. The results, obtained in selected systems, are discussed and compared to those arising from other procedures of population analysis.
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Affiliation(s)
- Alicia Torre
- Departamento de Química Física, Facultad de Ciencias, Universidad del País Vasco, Apdo. 644, E-48080, Bilbao, Spain.
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Alcoba DR, Lain L, Torre A, Bochicchio RC. Treatments of non-nuclear attractors within the theory of atoms in molecules. Chem Phys Lett 2005. [DOI: 10.1016/j.cplett.2005.03.078] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Bochicchio RC, Torre A, Lain L. Correlated holes and their relationships with reduced density matrices and cumulants. J Chem Phys 2005; 122:84117. [PMID: 15836030 DOI: 10.1063/1.1851976] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
This paper describes a matrix formulation for the correlated hole theory within the framework of the domain-averaged model in many electron systems (atoms, molecules, condensed matter, etc.). General relationships between this quantity and one-particle reduced density matrices for any independent particle or correlated state functions are presented. This formulation turns out to be suitable for computational purposes due to the straightforward introduction of cumulants of two-particle reduced density matrices within the quantum field structure. Numerical calculations in selected simple molecular systems have been performed in order to determine preliminary correlated values for such a quantity.
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Affiliation(s)
- R C Bochicchio
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina.
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Alcoba DR, Torre A, Lain L, Bochicchio RC. Energy decompositions according to physical space partitioning schemes. J Chem Phys 2005; 122:074102. [PMID: 15743216 DOI: 10.1063/1.1850906] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
This work describes simple decompositions of the energy of molecular systems according to schemes that partition the three-dimensional space. The components of those decompositions depend on one and two atomic domains thus providing a meaningful chemical information about the nature of different bondings among the atoms which compose the system. Our algorithms can be applied at any level of theory (correlated or uncorrelated wave functions). The results reported here, obtained at the Hartree-Fock level in selected molecules, show a good agreement with the chemical picture of molecules and require a low computational cost in comparison with other previously reported decompositions.
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Affiliation(s)
- Diego R Alcoba
- Departamento de Química Física, Facultad de Ciencias, Universidad del País Vasco, Apartado Postal 644, E-48080 Bilbao, Spain
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Lain L, Torre A, Bochicchio R. Studies of Population Analysis at the Correlated Level: Determination of Three-Center Bond Indices. J Phys Chem A 2004. [DOI: 10.1021/jp040014h] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Luis Lain
- Departamento de Quimica Fisica, Facultad de Ciencias, Universidad del Pais Vasco, Apdo. 644 E-48080 Bilbao, Spain
| | - Alicia Torre
- Departamento de Quimica Fisica, Facultad de Ciencias, Universidad del Pais Vasco, Apdo. 644 E-48080 Bilbao, Spain
| | - Roberto Bochicchio
- Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria 1428, Buenos Aires, Argentine
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Özkan İ, Kinal A, Balci M. Isomerizations of Bicyclo[2.1.0]pent-2-ene and Tricyclo[2.1.0.02,5]pentane into Cyclopenta-1,3-diene: A Computational Study by DFT and High-Level ab Initio Methods. J Phys Chem A 2003. [DOI: 10.1021/jp036792b] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- İlker Özkan
- Department of Chemistry, Middle East Technical University, 06531 Ankara, Turkey
| | - Armaǧan Kinal
- Department of Chemistry, Middle East Technical University, 06531 Ankara, Turkey
| | - Metin Balci
- Department of Chemistry, Middle East Technical University, 06531 Ankara, Turkey
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Bochicchio R, Lain L, Torre A. Determination of atomic valence indices from population analyses at correlated level. J Comput Chem 2003; 24:1902-9. [PMID: 14515372 DOI: 10.1002/jcc.10368] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This work carries out a study of atomic valences within molecular systems based on Mulliken and topological population analyses at correlated level. The use of the unpaired electron densities leads to suitable relationships between valences, free valence indices, and bond indices, which turn out to be quite useful for computational purposes. The results arising from both methods at correlated and uncorrelated levels are compared in a large series of chemical compounds. Several interesting conclusions are drawn out and analyzed in detail.
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Affiliation(s)
- R Bochicchio
- Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria 1428, Buenos Aires, Argentina.
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