On the determination of the long-range form of the interatomic potential from quasi-bound levels

Abstract

Calculations have been made on the quasi-bound (QB) vibrational levels of BeH and HgH to test the hypothesis that the position of such levels provides an accurate method of determining the form of the long range part of the interatomic potential and the dissociation energy. It is found that if the potential is required to join the spectroscopic RKR potential at some point r _sp then it is only for low J values that the positions of the QB levels are sensitive to the long range part of the potential. It is concluded that the available data on BeH and HgH does not allow an accurate estimate of the long range potential.