EFFECTS OF ELECTRONIC EXCITATIONS ON POTENTIAL-ENERGY SURFACES - SIMPLE-MODEL CALCULATIONS

The potential energy surfaces (PES) for excited states as well as for the ground state are calculated using a model consisting of an adatom and an (N - 1) atom chain. Two kinds of single-electron excitations ar e described on the basis of this model: an excitation from a state whi ch is localized near the surface to another localized stale and one fr om a non-localized state to another non-localized slate. The effects o f these excitations on the shapes of PES for the excited states are di scussed. It is shown hat the shapes of PES for the excited stales are affected by the excitations from localized to localized, whereas littl e effect comes from the excitations from non-localized to non-localize d.