Spin-orbit splitting in semiconductors and insulators from theab initiopseudopotential

In this Brief Report, we give the expressions required for using the vector (spin-orbit) part of the ab initio pseudopotential in a crystalline calculation. Inclusion of the spin-orbit interaction using the vector part of the pseudopotential in first order reproduces the measured spin-orbit splittings in Ge as well as the rare-gas solids and agrees with all-electron calculations.