Electronic Population Analysis of Molecular Wavefunctions

A general method for carrying out population analysis of wavefunctions calculated with arbitrary basis sets is presented. The difficulties in defining orbital populations is discussed. Results are presented for the sequence BF, CO, and N2 which indicate that back‐transfer of charge in the π bond cancels the normal transfer of the charge in the σ bond. Contrary to popular belief, the more electronegative element has the larger degree of hybridization in each case. The amount of promotion of 2s electrons is greater on the less‐electronegative element, as expected.