A computer simulation approach to the high pressure thermoelasticity of MgSiO 3 perovskite

• Published in: Physics of the earth and planetary interiors Vol. 98; no. 1; pp. 55 - 63
• Main Authors: Patel, Atul, Price, G.David, Matsui, Masanori, Brodholt, John P., Howarth, Richard J.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 1996
• ISSN: 0031-9201; 1872-7395
• DOI: 10.1016/S0031-9201(96)03172-X

We have used a combination of molecular dynamics and lattice dynamics simulation techniques to calculate the thermoelastic properties of MgSiO 3 perovskite over a wide range in P-T space. Our calculated values for the parameters which are of use in equation of state modelling are: Θ (K) = 1039, K 0 (GPa) = 250, K′ 0 = 4.0, V 0 (cm 3 mol −1 K −1) = 24.44, γ 0 = 1.97 and δ T 0 = 7.0. There is excellent agreement between our predicted values and the X-ray diffraction diamond anvil cell (XRD-DAC) experiments of Mao et al. (1991, J. Geophys. Res., 96: 8069–8079) but disagreement on the values of δ T 0 and γ when compared with the high pressure multi-anvil experiments of Wang et al. (1994, Phys. Earth Planet. Inter., 83: 13–41) and the fitted values of Anderson et al. (1995a, Phys. Earth Planet. Inter., 89: 35–49). In addition, the second Grüneisen parameter, q, was found to decrease with pressure, where q drops from 3.0 (0 GPa) to 1.7 at 100 GPa.