  We present a finite-temperature density functional theory investigation of
the nonequilibrium transient electronic structure of warm dense Li, Al, Cu, and
Au created by laser excitation. Photons excite electrons either from the inner
shell orbitals or from the valence bands according to the photon energy, and
give rise to isochoric heating of the sample. Localized states related to the
3d orbital are observed for Cu when the hole lies in the inner shell 3s
orbital. The electrical conductivity for these materials at nonequilibrium
states is calculated using the Kubo-Greenwood formula. The change of the
electrical conductivity, compared to the equilibrium state, is different for
the case of holes in inner shell orbitals or the valence band. This is
attributed to the competition of two factors: the shift of the orbital energies
due to reduced screening of core electrons, and the increase of chemical
potential due to the excitation of electrons. The finite temperature effect of
both the electrons and the ions on the electrical conductivity is discussed in
detail. This work is helpful to better understand the physics of laser
excitation experiments of warm dense matter.
