Electron correlation beyond the local density approximation: self-interaction correction ingadolinium

Abstract

We report on detailed first-principles calculations which focus on the magnetic andstructural properties of the (0001) surface of gadolinium. The electronic correlation withinthe localized 4f states is treated within the self-interaction correction (SIC), thus goingbeyond the local spin-density approximation. The ferromagnetic ground state is predictedcorrectly if the SIC is applied; the effect of surface relaxations on Heisenberg exchangeparameters and on the Curie temperature are addressed by Monte Carlo calculations. TheSIC also has a profound effect on the dispersion of the d surface states, due tohybridization of the 4f states with the 5d valence states. The best agreement withphotoemission experiments is obtained within the transition state approximation, whichtakes into account the orbital relaxation. The Rashba spin–orbit coupling in the dsurface states is fully captured by our relativistic multiple scattering approach.