Self-consistent augmented-plane-wave (APW) calculations of the T = 0 aluminum pressure-volume isotherm are reported from normal density to essentially the free-electron limit, and are compared to predictions based on statistical models. Two distinct density regimes are observed in which the APW and statistical model results differ fundamentally. In the first the L shell electrons are pressure ionized and in the second the K shell electrons are pressure ionized. The first of these occurs in the range 5-75 TPa, and the second in the range 2.3 x 10/sup 3/ - 1.1 x 10/sup 5/ TPa.

The effect of plasma temperature on reducing the wave-breaking amplitude of resonantly-driven fields is shown. Some applications to laser fusion are given.