Investigation of equation-of-state and melting behavior of rhodium up to 200 GPa

Equation-of-state (EOS) of face-centered cubic rhodium is studied using the moment method in statistical mechanics. Numerical calculations for rhodium metal have been implemented up to 200 GPa, and the bulk modulus K-0 and its first pressure derivative K-1 have been derived by fitting our EOS prediction with the BirchMurnaghan and Vinet EOSs. The Vinet EOS fit yields parameters K-0 = 244.57 GPa and K-1 = 5.50, while the Birch-Murnaghan EOS fit gives K-0 = 251.08 GPa and K-1 = 5.07. Furthermore, the pressure-dependent melting curve of rhodium has been investigated using the Force-Heat Equivalence Energy Density Principle approach, along with the obtained K-0 and K-1. Our theoretical melting curve shows good agreement with ab initio one-phase calculations up to 90 GPa. The theoretical melting curve of rhodium is accurately described by the Simon-Glatzel equation as T-m = (1 + P/21.8742)(0.4891).