Complex behavior of fluid lithium under extreme conditions.

Lithium is a prototypical simple metal at standard conditions which is well described within the nearly free electron model. However, by changing the density towards expanded or compressed states, the electrical conductivity shows strong and partly unexpected variations. We have performed quantum molecular dynamics simulations for fluid lithium for a wide range of densities and temperatures in order to derive the equation of state, the electrical conductivity, and information about structural and electronic changes along the expansion or compression. Based on these results, we can give a consistent description of the electrical conductivity from the nonmetallic expanded fluid up to the degenerate electron liquid at high densities.