Computer simulation and visualization of vacancy defects in MgSiO \u3csub\u3e3\u3c/sub\u3e perovskite

We have performed the first-principles simulations within the local density and pseudopotential approximations to investigate the effects of pressure on the energetics and atomic and electronic structural behaviour of vacancy defects in MgSiO perovskite. The simulations use a supercell containing 160 atoms whose positions are fully optimized for each defective system. Schottky formation energy is shown to increase by a factor of 2.5 over the pressure regime (0 to 150 GPa) studied. The calculated three-dimensional datasets for atomic configuration and electron charge density are visualized in detail. It is shown that these point defects induce substantial distortions in the surrounding atomic and electronic structures, and these distortions remain nearly unchanged with pressure. © 2006 IOP Publishing Ltd.