Exchange Energy on Alkali Diatomic Molecules: Period Effects

Abstract

The exchange energy in the long-range near-dissociation region is analyzed for the ground electronic states of homo- and heteronuclear alkali diatomic molecules. The analysis is based on the use of the functional formAe−arto represent this exchange term. A period effect is observed in the values of both parameters and the exponent parameteraappears to approach an asymptotic limit for the heavier molecules. The results obtained in this study also suggest that some care must be taken in using even this function to represent the exchange energy.