A THEORETICAL-STUDY OF THE VIBRATIONAL DEPENDENCE OF THE NUCLEAR-QUADRUPOLE COUPLING-CONSTANTS OF SOME DIATOMIC-MOLECULES

The nuclear quadrupole coupling constant was calculated as a function of inter nuclear distance for nine quadrupolar nuclei in eight diatomi c molecules by the STO 321G method. From the value of the field-gradie nt and its first and second derivatives the vibrational dependence of the coupling constants were calculated and shown to compare satisfacto rily with experiment. The behaviour of the field-gradient as a functio n of inter nuclear distance can in most cases be rationalized in terms of the field-gradient that will arise for the infinitely separated at oms.