Optical properties of BP, BAs and BSb compounds under hydrostatic pressure

We present results of a study of the electronic and optical properties of zinc-blende BP, BAs and BSb compounds. The refractive index and its variation with hydrostatic pressure are well described. Accurate calculation of linear optical function (index of refraction and its pressure derivative, and both imaginary and real parts of dielectric function) are performed in photon energy range up to 30eV. We have worked out calculations non-relativistic with the FP-LAPW method using the WIEN 97 code, these calculations are based on the density functional theory (DFT) with the local density approximation (LDA). We compared our results with those found by pseudopotential plane wave approach