How electrons still guard the space: Electron number distribution functions based on QTAIM∩ELF intersections

Area of Science:

• Quantum Chemistry
• Theoretical Chemistry
• Computational Chemistry

Background:

• Understanding electron spatial distribution in molecules is crucial for chemistry.
• Topological methods like Quantum Theory of Atoms in Molecules (QTAIM) and Electron Localization Function (ELF) partition molecular space into chemically relevant regions.
• Electron Distribution Functions (EDFs) offer statistical insights into electron distribution within these domains.

Purpose of the Study:

• To develop a more refined analysis of molecular electron distribution.
• To calculate Electron Distribution Functions (EDFs) within the intersection of QTAIM and ELF domains.
• To investigate the combined distribution of electrons between atoms and Lewis entities (bonds, lone pairs).

Main Methods:

• Calculation of EDFs in the intersection domains of QTAIM and ELF.
• Application to main group element hydrides (AHn) and diatomic molecules (CO, NO, BeO).
• Exploration of electron correlation effects using Hartree-Fock (HF), Density Functional Theory (DFT) (B3LYP), and CASSCF methods.

Main Results:

• The QTAIM ∩ ELF intersection approach yields an exceptionally detailed picture of electron distribution.
• This method successfully combines the distribution of electrons between atoms and Lewis entities.
• The study demonstrates the applicability to various molecular systems and computational levels.

Conclusions:

• Combining QTAIM and ELF domains for EDF calculations offers unprecedented insight into molecular electron distribution.
• This fine-grained analysis provides a powerful tool for understanding chemical bonding and electronic structure.
• The approach is versatile and applicable across different computational chemistry methods.