Distortion of interacting atoms and ions

Abstract

The distortion of atoms in HeNe and ions in LiF and NaCl is studied by use of non-orthogonal, least distorted, localized molecular orbitals in the restricted Hartree-Fock approximation. We find that the least distortion criterion is effective in producing localized orbitals. In addition we find that point-by-point the localized orbitals differ little from the Hartree-Fock orbitals of the corresponding atoms or ions, although the differences are energetically important. We infer from our calculations that the effective potential which distorts atomic orbitals into localized molecular orbitals must be quite weak.