AB-INITIO MOLECULAR-DYNAMICS WITH EXCITED ELECTRONS

A method to do ab initio molecular dynamics suitable for metallic and electronically hot systems is described. It is based on a density func tional which is costationary with the finite-temperature functional of Mermin, with state being included with possibly fractional occupation numbers. Optimization with respect to density only, rather than state s and occupation numbers, is necessary. As an illustration, the method is used to calculate structure and dynamics in dense hot hydrogen.