The electronic band structure of relaxed and biaxially strained Si, Ge, III-V semiconductors (GaAs, GaSb, InAs, InSb, InP) and their alloys (InxGa1-xAs, InxGa1-xSb) on different interface orientations, (001), (110) and (111), is calculated using the nonlocal empirical pseudopotential method (EPM) with spin-orbit interaction using cubic spline interpolations of the atomic form factors. For III-V alloys, the virtual crystal approximation (VCA) is employed to calculate the band gap bowing parameters. Calculated results such as band gap (direct and indirect), band gap bowing parameters, and deformation potentials are fitted to the experimental data when available. Deformation potentials are determined using linear deformation potential theory when the small biaxial strain (in-plane) is present.