The equations of state of statically compressed palladium and rhodium

The pressure-volume equations of state of palladium and rhodium statically compressed in neon are presented. Vinet fits give parameters for palladium. V-0 = 58.678(73) angstrom(3), B-0 = 189.3(30) GPa, B-0 ' = 5.473(63), and rhodium. V-0 = 55.062(63) angstrom(3), B-0 = 241.3(65) GPa, B-0 ' = 5.34(24). Both metals are observed to react with hydrocarbons under pressure to form hydrides. Existing equations of state are discussed with regard to potential inadvertent hydrogen contamination as a source for discrepancies and anomalous fitted parameters.