HR: 1340h
AN: MR23C-1522    [Abstracts]
TI: Pressure Correction In First-Principles Calculations: MgO As An Example
AU: * Lee, S
EM: shlee@phy.cuhk.edu.hk
AF: Physics Department, The Chinese University of Hong Kong, CUHK, Shatin, N.T. Hong Kong, Hong Kong, 852,
AU: Wan, J
EM: jwan@phy.cuhk.edu.hk
AF: Physics Department, The Chinese University of Hong Kong, CUHK, Shatin, N.T. Hong Kong, Hong Kong, 852,
AB: First-principles (FP) calculations based on Density functional theory (DFT) has been widely used in the studies of structural, thermoelastic, rheological, as well as electronic properties of Earth-forming materials. The exchange correlation term is, however, implemented based on various approximations and it is believed to be the main reason of discrepancies between experiments and theories. In this work, by using MgO as an example, we examine the difference between the pressures calculated by two commonly used versions of exchange correlation approximation, namely, the local density approximation (LDA) and the generalized gradient approximation (GGA). We have performed extensive first-principles calculations at various temperatures and found that the pressure difference vary systematically with temperature and simulation cell volume. Our findings may be useful to the prediction of mineral properties at thermodynamic conditions compatible to deep planets
DE: 0500 COMPUTATIONAL GEOPHYSICS (3200, 3252, 7833)
SC: Mineral and Rock Physics [MR]
MN: 2007 Fall Meeting