Contributions of IQA electron correlation in understanding the chemical bond and non-covalent interactions

Autor(es)

Silva, Arnaldo F. ^{[1, 2]} ; Duarte, Leonardo J. ^{[3, 1, 2]} ; Popelier, Paul L. A. ^{[1, 2]}

Afiliação do(s) autor(es)

^[1] MIB, 131 Princess St, Manchester M1 7DN, Lancs - England

^[2] Univ Manchester, Dept Chem, Oxford Rd, Manchester M13 9PL, Lancs - England

^[3] Univ Estadual Campinas, Inst Quim, CP 6154, BR-13083970 Campinas, SP - Brazil

• Tipo de documento: Artigo de Revisão
• Fonte: STRUCTURAL CHEMISTRY; v. 31, n. 2 FEB 2020.
• Citações Web of Science: 0

Resumo

The quantum topological energy partitioning method Interacting Quantum Atoms (IQA) has been applied for over a decade resulting in an enlightening analysis of a variety of systems. In the last three years we have enriched this analysis by incorporating into IQA the two-particle density matrix obtained from Moller-Plesset (MP) perturbation theory. This work led to a new computational and interpretational tool to generate atomistic electron correlation and thus topologically based dispersion energies. Such an analysis determines the effects of electron correlation within atoms and between atoms, which covers both bonded and non-bonded ``through -space{''} atom-atom interactions within a molecule or molecular complex. A series of papers published by us and other groups shows that the behavior of electron correlation is deeply ingrained in structural chemistry. Some concepts that were shown to be connected to bond correlation are bond order, multiplicity, aromaticity, and hydrogen bonding. Moreover, the concepts of covalency and ionicity were shown not to be mutually excluding but to both contribute to the stability of polar bonds. The correlation energy is considerably easier to predict by machine learning (kriging) than other IQA terms. Regarding the nature of the hydrogen bond, correlation energy presents itself in an almost contradicting way: there is much localized correlation energy in a hydrogen bond system, but its overall effect is null due to internal cancelation. Furthermore, the QTAIM delocalization index has a connection with correlation energy. We also explore the role of electron correlation in protobranching, which provides an explanation for the extra stabilization present in branched alkanes compared to their linear counterparts. We hope to show the importance of understanding the true nature of the correlation energy as the foundation of a modern representation of dispersion forces for ab initio, DFT, and force field calculations. (AU)

• Processo FAPESP: 14/21241-9 - Inclusão de polarização na descrição de aminoácidos e peptídeos utilizando multipolos atômicos calculados a partir de densidades eletrônicas
• Beneficiário: Arnaldo Fernandes da Silva Filho
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 17/22741-3 - Uso de multipolos atômicos e desenvolvimento de modelos de machine learning na investigação de estados de transição
• Beneficiário: Leonardo José Duarte
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 18/24844-7 - Uso de tensores polares atômicos e parâmetros QCT para treinar um modelo de machine learning e prever constantes de Hammett
• Beneficiário: Leonardo José Duarte
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado Direto