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 functional 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 states and occupation numbers, is necessary. As an illustration, the method is used to calculate structure and dynamics in dense hot hydrogen.