Effects of pressure and temperature on the isothermal bulk modulus of CaO

Abstract

Molecular dynamics (MD) simulations have been performed to investigate the effects of pressure and temperature on the isothermal bulk modulus of CaO using pair-wise interactions that include polarization effects through the shell model (SM). The dependence of isothermal bulk modulus B T of CaO on the compression ratio V/ V 0 and pressure P have been obtained from MD runs at T=300 K, and compared with the available experimental data and other theoretical results. A good agreement between theory and experiment is obtained. Meanwhile, B T dependence on temperature T at zero pressure is investigated. At extended pressure and temperature ranges, SM–MD method has also been carried out for predicting the P– V– T equation of state and isothermal bulk modulus at different temperatures along the isotherms 0, 1000, 2000, 3000, and 4000 K, and at different pressures along the isobars 5, 15, 30, 40, and 50 GPa for CaO, respectively.