Exploring the nature of electron-pair bonds: an energy decomposition analysis perspective

Yang Zhang; Xun Wu; Peifeng Su; Wei Wu

doi:10.1088/1361-648X/ac6bd9

Exploring the nature of electron-pair bonds: an energy decomposition analysis perspective

J Phys Condens Matter. 2022 May 16;34(29). doi: 10.1088/1361-648X/ac6bd9.

Authors

Yang Zhang¹, Xun Wu¹, Peifeng Su¹, Wei Wu¹

Affiliation

¹ The State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, iChEM, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, People's Republic of China.

PMID: 35487208
DOI: 10.1088/1361-648X/ac6bd9

Abstract

In this paper, the nature of electron-pair bonds is explored from an energy decomposition perspective. The recently developed valence bond energy decomposition analysis (VB-EDA) scheme is extended for the classification of electron-pair bonds, which divides the bond dissociation energy into frozen, reference state switch, quasi-resonance and polarization terms. VB-EDA investigations are devoted to a series of electron-pair bonds, including the covalent bonds (H-H, H₃C-CH₃, H₃C-H, and H₂N-NH₂), the ionic bonds (Na-Cl, Li-F), the charge-shift (CS) bonds (HO-OH, F-F, Cl-Cl, Br-Br, H-F, F-Cl, H₃Si-F and H₃Si-Cl), and the inverted central carbon-carbon bond in [1.1.1] propallene. It is shown that the VB-EDA approach at the VBSCF level is capable of predicting the characters of the electron-pair bonds. The perspective from VB-EDA illustrates that a relatively high value of quasi-resonance term indicates a CS bond while a large portion of polarization term suggests a classical covalent bond.

Keywords: charge-shift bonds; electron-pair bonds; energy decomposition analysis; valence bond theory.