In this paper we present a comprehensive study of the tetrahedral semiconductor ZnSe crystallizing in the zincblende structure. The electronic structure of ZnSe has been determined first using the ab initio self-consistent linear muffin-tin orbital method with a local-density form of the exchange-correlation functional. Then it has been adjusted to reproduce the experimental energy positions of the Zn 3d bands and of the optical gap. The adjusted electronic structure, densities of states and interband optical properties are presented and compared with previous calculations. Good agreement with experimental photoemission and bremsstrahlung isochromat measurements was found after including an energy-dependent lifetime broadening. We measured the reflectivity of ZnSe with high resolution from 4 to 30 eV and the high-energy region of the spectra has been interpreted on the basis of the present calculation
