  We have performed quantum molecular dynamic simulations for warm dense
polystyrene at high pressures. The principal Hugoniot up to 790 GPa is derived
from wide range equation of states, where contributions from atomic ionizations
are semiclassically determined. The optical conductivity is calculated via the
Kubo-Greenwood formula, from which the dc electrical conductivity and optical
reflectivity are determined. The nonmetal-to-metal transition is identified by
gradual decomposition of the polymer. Our results show good agreement with
recent high precision laser-driven experiments.
