Pressure dependence of the electronic structure in Ge, GaP and InP semiconductors at room temperature

The electronic structure of Ge, GaP and InP semiconductors under hydrostatic pressure based on the empirical pseudopotential method have been reported. The pressure coefficients, pressure dependent form factors, of the main band gaps at \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \underline{\Upgamma } ,\;\underline{\text{X}} $$\end{document} and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \underline{\text{L}} $$\end{document} symmetry points in the Brillouin zone have been calculated. We have found that most of the values of the electronic energy bands were more sensitive to the pressure dependent form factors associated with the reciprocal lattice vectors of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \left| {\Updelta \underline{\underline{{\mathbf{G}}}} } \right|^{2} = 11 $$\end{document} than any other value. Our calculations for the energy gaps of the semiconductors under investigation at different pressures have been found to be in excellent agreement with available experimental data.