Integrated spatial electron populations in molecules: Application to simple molecules

The electron projection function P ( x , z ) = ∫ ρ( x , y , z ) dy is used to evaluate charge transfer and covalency in two series of molecules, LiX and CH 3 X (X = Li, BeH, BH 2 , CH 3 , NH 2 , OH, and F), with wavefunctions derived from STO‐3G, 4‐31G, and, in some cases, 6‐31* ab initio calculations. The precision of the method and comparison with Mulliken populations analysis are described. Particular attention is given to CH 3 Li which by our criteria is wholly ionic.