Electronic Grüneisen parameter in the shock Hugoniot equation of state of aluminum

The shock Hugoniot equation of state for aluminum has been computed, using the pseudopotential method. The nuclear Grüneisen parameters, used in evaluating the ionic vibration contributions, have been derived from phonon frequencies. The computed electronic Grüneisen-parameter values depart considerably from the value 0.5, used often in analyzing shock-compression experiments. This leads to different Hugoniot temperatures compared with those derived by Al'tshuler et al., although the $P-V$ curve is in good agreement with their experimental results.