학술논문

How electrons still guard the space: Electron number distribution functions based on QTAIM∩ELF intersections.
Document Type
Article
Source
Journal of Chemical Physics. 4/14/2024, Vol. 160 Issue 14, p1-17. 17p.
Subject
*ELECTRON distribution
*ATOMS in molecules theory
*DISTRIBUTION (Probability theory)
*ELECTRON density
*ELECTRONS
Language
ISSN
0021-9606
Abstract
Despite the importance of the one-particle picture provided by the orbital paradigm, a rigorous understanding of the spatial distribution of electrons in molecules is still of paramount importance to chemistry. Considerable progress has been made following the introduction of topological approaches, capable of partitioning space into chemically meaningful regions. They usually provide atomic partitions, for example, through the attraction basins of the electron density in the quantum theory of atoms in molecules (QTAIM) or electron-pair decompositions, as in the case of the electron localization function (ELF). In both cases, the so-called electron distribution functions (EDFs) provide a rich statistical description of the electron distribution in these spatial domains. Here, we take the EDF concept to a new fine-grained limit by calculating EDFs in the QTAIM ∩ ELF intersection domains. As shown in AHn systems based on main group elements, as well as in the CO, NO, and BeO molecules, this approach provides an exquisitely detailed picture of the electron distribution in molecules, allowing for an insightful combination of the distribution of electrons between Lewis entities (such as bonds and lone pairs) and atoms at the same time. Besides mean-field calculations, we also explore the impact of electron correlation through Hartree–Fock (HF), density functional theory (DFT) (B3LYP), and CASSCF calculations. [ABSTRACT FROM AUTHOR]