Empirical equation of state theories at ultra-high pressures

New 300 K isotherms of Al, Cu and Pb, up to 1 TPa and V/V<SUB>0</SUB>=0.3, recently given by Nellis et al., have been used to test the validity of Birch-Murnaghan and universal equations of state in this compression range. The universal equation is found to be better. The reasons for its agreement or departure from the data of Nellis et al. are also discussed