摘要
IntroductionThealkalihalidediatomicmoleculesprovideatypicalcurvecrosingproblem[1].Theoutstandingnonadiabaticbehaviorofthechem...
Ab initio VB calculations were used to determine the accurate spectroscopic parameters of the ground states of LiF and NaF. A set of potential energy curves corresponding to the ground states including ionic and covalent interactions, pure ionic interaction and covalent interaction were generated using the VBSCF method. Curve crossing in the dissociation processes of LiF and NaF was discussed. The optimized VB wave functions suggest that LiF and NaF are of high ionicity, and their ionic weights are 86 2% and 94 6%, respectively. NaF has a higher ionicity. The main difference between atom F and ion F - and the effect of the proper description of this difference on dissociation energies were investigated.