AB initio studies of HeNi and HeCu interaction potentials

Cluster model configuration interaction calculations on HeNi14 and HeCu14, have been performed for determining helium surface interaction potentials. For Ni, the interaction potentials are found to be similar for atop atom and mid-bond He trajectories, while for Cu, the atop atom site is much more repulsive in accord with the He diffraction data. The calculated He-Cu potentials are fit to within 15% by V= αρ, for a given vertical distance above the surface, where ρ is the substrate charge density. For HeNi, the variation in a is greater. © 1985.