HOT-ELECTRONS AND THE APPROACH TO METALLIC BEHAVIOR IN K-X(KCL)(1-X)

The approach to the metallic phase of molten K-x(KCl)(1-x) mixtures is studied using ab initio molecular dynamics based on finite-temperatur e density functional theory. The finite electronic temperature is foun d to result in new and unexpected effects. In particular, we observe a thermally induced lowering of the predicted DC conductivity, which gr eatly improves the agreement with the experiment, and a widening of th e HOMO-LUMO energy gap. We expect that these are genuinely new physica l effects which could be observed also in other systems.