Projected density of states (PDOS) for the H- negative ion located at fixed distances in front of a Na/Cu(111) surface: Z = 15 a.u. (full line) and Z = 16 a.u. (dash line). IS1: n = 1 image state. IS2: n = 2 image state.
This graph and data were contributed by Bogdana Bahrim, Lamar University.