First-Principles Study of Orthorhombic Perovskites MgSiO3 up to 120GPa and Its Geophysical Implications
DENG Li-Wei1, ZHAO Ji-Jun2,1, JI Guang-Fu3, GONG Zi-Zheng4,1, WEI Dong-Qing5,6
1Institute of High Pressure and High Temperature Physics, Southwest Jiaotong University, Chengdu 610031
2College of Advanced Science and Technology, Dalian University of Technology, Dalian 116023
3Laboratory for Shock Wave and Detonation Physics, Institute of Fluid Physics, Mianyang 621900
4Beijing Institute of Spacecraft Environment Engineering, Beijing 100094
5College of Life Science and Technology, Shanghai Jiao Tong University, Shanghai 200240
6Center for Research in Molecular Modeling (CERMM), Concordia University, Montreal, Canada
First-Principles Study of Orthorhombic Perovskites MgSiO3 up to 120GPa and Its Geophysical Implications
DENG Li-Wei1;ZHAO Ji-Jun2,1;JI Guang-Fu3;GONG Zi-Zheng4,1;WEI Dong-Qing5,6
1Institute of High Pressure and High Temperature Physics, Southwest Jiaotong University, Chengdu 610031
2College of Advanced Science and Technology, Dalian University of Technology, Dalian 116023
3Laboratory for Shock Wave and Detonation Physics, Institute of Fluid Physics, Mianyang 621900
4Beijing Institute of Spacecraft Environment Engineering, Beijing 100094
5College of Life Science and Technology, Shanghai Jiao Tong University, Shanghai 200240
6Center for Research in Molecular Modeling (CERMM), Concordia University, Montreal, Canada
Abstract： High-pressure behaviour of orthorhombic MgSiO3 perovskite crystal is simulated by using the density functional theory and plane-wave pseudopotentials approach up to 120GPa pressure at zero temperature. The lattice constants and mass density of the MgSiO3 crystal as functions of pressure are computed, and the corresponding bulk modulus and bulk velocity are evaluated. Our theoretical results agree well with the high-pressure experimental data. A thermodynamic method is introduced to correct the temperature effect on the 0-K first-principles results of bulk wave velocity, bulk modulus and mass density in lower mantle P/T range. Taking into account the temperature corrections, the corrected mass density, bulk modulus and bulk wave velocity of MgSiO3-perovskite are estimated from the first-principles results to be 2%, 4%, and 1% lower than the preliminary reference Earth model (PREM) profile, respectively, supporting the possibility of a pure perovskite lower mantle model.
(Density functional theory, local density approximation, gradient and other corrections)
引用本文:
DENG Li-Wei;ZHAO Ji-Jun;JI Guang-Fu;GONG Zi-Zheng;WEI Dong-Qing;. First-Principles Study of Orthorhombic Perovskites MgSiO3 up to 120GPa and Its Geophysical Implications[J]. 中国物理快报, 2006, 23(8): 2334-2337.
DENG Li-Wei, ZHAO Ji-Jun, JI Guang-Fu, GONG Zi-Zheng, WEI Dong-Qing,. First-Principles Study of Orthorhombic Perovskites MgSiO3 up to 120GPa and Its Geophysical Implications. Chin. Phys. Lett., 2006, 23(8): 2334-2337.
2006, Vol. 23 
