Valencies and bond indices for the elements from hydrogen to chlorine

Abstract

Calculations, within the CNDO framework, have been performed on a wide range of molecules containing elements of the first and second rows of the Periodic Table. By use of the density matrix elements, the valencies of all the atoms are calculated and their significance is discussed. It is found that in many molecules the calculated valencies are essentially the same as the classical ones. Deviations from ‘normal’ valencies are discussed in terms of the chemistry of the particular molecule. Anisotropies for some of the atoms and bond indices for the bonds in selected molecules are also calculated and are shown to correlate well with the electronic distribution.