The performance of exchange-correlation functionals in describing electron density parameters of saddle point structures along chemical reactions

Autor(es)

Macedo, Gabriel Kossaka ; Andrade Haiduke, Roberto Luiz

• Tipo de documento: Artigo Científico
• Fonte: Journal of Computational Chemistry; v. 43, n. 27, p. 9-pg., 2022-09-02.

Resumo

This work is focused on evaluating the performance of exchange-correlation functionals from density functional theory in providing descriptor values derived from the electron density of saddle point structures (transition states) in chemical reactions. The properties investigated were obtained from the quantum theory of atoms in molecules, including atomic charges and electron density topological data at the bond critical points. In addition, parameters from the Interacting quantum atom energy partition were used as well in this comparative study. The reference values are attained in coupled cluster calculations with iterative single and double excitations (CCSD). Six elementary reactions are considered here: CO + H-2 <-> H2CO, CO + H2O <-> HCOOH, HCN <-> HNC, H + F-2 <-> HF + F, H + N-2 <-> HN2, and H + CO <-> HCO. In general, the BB1K functional (hybrid-meta-generalized gradient approximation) provides the best description of these properties. Our study indicates that an intermediate percentage of nonlocal exact exchange, around 40%-55% (perhaps even larger), is probably required for attaining more accurate values with actual functionals, although this condition is not able of explaining all the trends observed. (AU)

• Processo FAPESP: 14/23714-1 - Cálculos relativísticos de estrutura eletrônica para avaliação de novos conjuntos de funções de base sem prolapso variacional
• Beneficiário: Roberto Luiz Andrade Haiduke
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 18/12675-6 - Análise da estabilidade de estados de transição em reações químicas com uso de ferramentas da teoria quântica de átomos em moléculas
• Beneficiário: Gabriel Kossaka Macedo
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto