Energy decomposition analysis

Abstract The energy decomposition analysis (EDA) is a powerful method for a quantitative interpretation of chemical bonds in terms of three major expressions. The instantaneous interaction energy Δ E int between two fragments A and B in a molecule A–B is partitioned in three terms, namely, (1) the quasiclassical electrostatic interaction Δ E elstat between the fragments, (2) the repulsive exchange (Pauli) interaction Δ E Pauli between electrons of the two fragments having the same spin, and (3) the orbital (covalent) interaction Δ E orb , which comes from the orbital relaxation and the orbital mixing between the fragments. The latter term can be decomposed into contributions of orbitals with different…