  We use an explicitly isochoric two-temperature theory where the ion
temperature is not assumed to be equal to the electron temperature, to analyze
recent X-ray laser scattering data for Aluminum in the ultra-fast-matter (UFM)
regime up to 6 eV, obtained at the Standford Linac Coherent Light Source
(LCLS). The observed surprisingly low conductivities are explained by including
strong electron-ion scattering effects using the phase shifts calculated via
the density-functional neutral-pseudo-atom model (NPA). The applicability of
the Mermin model to UFM is questioned. The static and dynamic conductivity,
complex collision frequency and the plasmon line-shape are evaluated within a
Born approximation and without the use of the Mermin response. This approach,
where all needed quantities are obtained from the NPA model, provides good
agreement with the reported experimental results.
