Spin–orbit coupling within a two-component density functional theory approach: theory, implementation and first applications

An implementation of spin–orbit coupling within a two-component generalization of the density functional code MAGIC is described. The spin–orbit operator is represented in the effective one-electron mean-field approximation and included into the Fock matrix within an iterative self-consistent scheme. First tests have been carried out for the spin–orbit splitting of several atoms. The spin–orbit effect on the bond distance and harmonic frequency of some diatomics has also been determined. This scheme allows to include spin–orbit in a simple way and can be efficiently used to treat large systems.