Calculated spin-orbit splitting of all diamondlike and zinc-blende semiconductors:: Effects of p1/2 local orbitals and chemical trends -: art. no. 035212

We have calculated the spin-orbit (SO) splitting Delta(SO)=epsilon(Gamma(8v))-epsilon(Gamma(7v)) for all diamondlike group IV and zinc-blende group III-V, II-VI, and I-VII semiconductors using the full potential linearized augmented plane wave method within the local density approximation. The SO coupling is included using the second-variation procedure, including the p(1/2) local orbitals. The calculated SO splittings are in very good agreement with available experimental data. The corrections due to the inclusion of the p(1/2) local orbital are negligible for lighter atoms, but can be as large as similar to250 meV for 6p anions. We find that (i) the SO splittings increase monotonically when anion atomic number increases; (ii) the SO splittings increase with the cation atomic number when the compound is more covalent such as in most III-V compounds; (iii) the SO splittings decrease with the cation atomic number when the compound is more ionic, such as in II-VI and the III-nitride compounds; (iv) the common-anion rule, which states that the variation of Delta(SO) is small for common-anion systems, is usually obeyed, especially for ionic systems, but can break down if the compounds contain second-row elements such as BSb; (v) for IB-VII compounds, the Delta(SO) is small and in many cases negative and it does not follow the rules discussed above. These trends are explained in terms of atomic SO splitting, volume deformation-induced charge renormalization, and cation-anion p-d couplings.