摘要
Constant temperature and pressure molecular dynamics （MD） simulations are performed to investigate the thermal expansivity of MgO at high pressure, by using effective pair-wise potentials which consist of Coulomb, dispersion, and repulsion interactions that include polarization effects through the shell model （SM）. In order to take into account non-central forces in crystals, the breathing shell model （BSM） is also introduced into the MD simulation. We present a comparison between the volume thermal expansion coefficient a dependences of pressure P at 300 and 2000 K that are obtained from the SM and BSM potentials and those derived from other experimental and theoretical methods in the case of MgO. Compared with the results obtained by using the SM potentials, the MD results obtained by using BSM potentials are more compressible. In an extended pressure and temperature range, the α value is also predicted. The properties of MgO in a pressure range of 0-200 GPa at temperatures up to 3500K are summarized.
Constant temperature and pressure molecular dynamics （MD） simulations are performed to investigate the thermal expansivity of MgO at high pressure, by using effective pair-wise potentials which consist of Coulomb, dispersion, and repulsion interactions that include polarization effects through the shell model （SM）. In order to take into account non-central forces in crystals, the breathing shell model （BSM） is also introduced into the MD simulation. We present a comparison between the volume thermal expansion coefficient a dependences of pressure P at 300 and 2000 K that are obtained from the SM and BSM potentials and those derived from other experimental and theoretical methods in the case of MgO. Compared with the results obtained by using the SM potentials, the MD results obtained by using BSM potentials are more compressible. In an extended pressure and temperature range, the α value is also predicted. The properties of MgO in a pressure range of 0-200 GPa at temperatures up to 3500K are summarized.
基金
Project supported by the National Natural Science Foundation of China (Grant Nos 10674120 and 10774121)
the 'Qing Lan' Talent Engineering Funds by Lanzhou Jiaotong University of China (Grant No QL-06-22A)
the Research Foundation from Ministry of Education of China (Grant No 209127)
