Real-space pseudopotential method for calculating magnetocrystalline anisotropy

We present a real-space pseudopotential method for calculating magnetocrystalline anisotropy within relativistic density-functional theory. The spin-orbit interaction, a fundamental origin of magnetocrystalline anisotropy, is incorporated with norm-conserving pseudopotentials expressed on a real-space grid. We demonstrate the utility of our method by calculating the magnetocrystalline anisotropy constant, K-1, of YCo5, which is a prototype compound with large K-1. Our calculated K-1 agrees with previous theoretical work. We show that our formalism also works for describing magnetocrystalline anisotropy in other transition-metal compounds, such as Mn2Ga and FeNi, which have modest values for K-1. Our real-space pseudopotential method is well suited for a parallel computing environment and is an efficacious approach to solving the relativistic Kohn-Sham equations, which include spin-orbit effects as well as noncollinear magnetism.