Quantal density functional theory of excited states - art. no. 113002

We explain by quantal density functional theory the physics of mapping from any bound nondegenerate excited state of Schrodinger theory to an S system of noninteracting fermions with equivalent density and energy. The S syste m may be in a ground or excited state. In either case, the highest occupied eigenvalue is the negative of the ionization potential. We demonstrate thi s physics with examples. The theory further provides a new framework for ca lculations of atomic excited states including multiplet structure.