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

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 GSFs are determined from first-principle calculations using the VASP code. 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), ½[110](001) and ½[110](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.