A concept of charge and valence for ab initio wave functions

A modified scheme of a previously developed concept of atomic valence numbers in molecules is presented. The relation to population analysis is demonstrated. The scheme is suitable for ab initio wave functions with extended basis sets. The procedure involved a combination of symmetric orthogonalization and contraction of the basis set. The method is used for a systematic investigation of a series of compounds with first‐row atoms from Li to F. The predicted atomic charges and valence numbers are in line with results from infrared spectroscopy and multipole moment analysis.