Vibrational smearing of deformation densities in diatomic molecules. An application of Hartree-Fock-Slater SCF calculations

The smearing of the deformation density in the diatomics H₂, CH, Bell, CO and N₂, caused by internal vibration, is calculated using a large number of LCAO Hartree-Fock-Slater electronic wave- functions. Both the effect of anharmonicity and the thermal population of rotational and vibrational states at 300 K are considered. The main conclusion is that the effect of the smearing is very small for these molecules. Compared to the effect of the anharmonic zero-point vibration upon the charge deformation density, the influence of including higher states at 300 K is negligible.