Peierls–Nabarro model for dislocations in MgSiO₃post-perovskite calculated at 120 GPa from first principles

Abstract

Abstract\n We present here the first numerical modelling of dislocations in MgSiO3 post-perovskite at 120 GPa. The dislocation core structures and properties are calculated through the Peierls-Nabarro model using the Generalized Stacking Fault (GSF) results as a starting model. The GSF are determined from first-principle calculations using the VASP code. The dislocation properties such as planar core spreading and Peierls stresses are determined for the following slip systems: [100](010), [100](001), [100](011), [001](010), [001](110), [001](100), [010](100), [010](001), ?[110](001) and ?[110]( ). Our results confirm that the MgSiO3 post-perovskite is a very anisotropic phase with a plasticity dominated by dislocation glide in the (010) plane