Density functional theory for excited states

Abstract

AbstractIn this article, we justify the use of standard Kohn‐Sham (KS) band structure theory for the calculation of the low‐energy spectrum of metals and the density of states. For the higher spectrum, one can start the KS excited‐state calculations by using as the first‐order approximation the spin orbitals of the ground state. We next deal with the problem of degenerate states by using the subspace theory minimum principle. © 1995 John Wiley & Sons, Inc.