Model-potential method for the calculation of atom-rare-gas interactions: application to the Na-Ne system

Results of model-potential calculations for the ground-state and the first nine excited-state molecular curves of the Na-Ne system are presented. A two-parameter model potential for the electron-neon interaction can be fitted to scattering data. The molecular curves are not affected by the uncertainty of the data. The introduction of a non-local orthogonality condition to the neon core orbitals is discussed. For internuclear distances R>or=5 au, the authors' results agree within 5% with the laser spectroscopy determination of the well in the X 2 Sigma and A 2 Pi potential curves, and with the far wing profile determined by York et al., (1975). A blue satellite is predicted at 1224 cm -1 . The accuracy at smaller internuclear distances is limited by the lack of precision in the NaNe + core-core repulsion. In contrast with pseudopotential calculations, a 450 cm -1 well is obtained in the delta 3d curve at 4.5 au. The sigma 4s, sigma 3d and sigma 4p states present a barrier at 10 au and a well at 4.5 au.