Electronic Band Structure and Wannier Exciton States in Solid Krypton

The electronic band structure of solid krypton has been calculated by a combined tight-binding and orthogonalized plane wave approach first introduced by Knox and Bassani. The crystal potential, constructed as a sum of quasiatomic potentials, contains an exchange potential which has been made to approximate closely the crystal Slater exchange potential. Spin-orbit splittings have been computed, and effective masses have been obtained at points of high symmetry in the Brillouin zone. The smallest computed gap between valence and conduction bands is "direct," is located at $\Gamma (\mathrm{k}=0)$, and has a magnitude of 11.3±1.0 eV, in agreement with the direct gap of 11.8 eV inferred by Baldini on the basis of optical absorption data. Computed Wannier exciton absorption lines at $\Gamma$ are also in agreement with Baldini's results.