Electronic properties of GaN at high-pressure from local density and generalized gradient approximations

Electronic properties of zinc-blende GaN under high-pressure up to 12 Gpa are obtained from density-functional-theory calculations using an ab initio total energy pseudopotential technique within the local-density and the generalized gradient approximations. Quantities such as, band-gap deformation potentials and pressure coefficients of main critical-point band gaps, valence band width, and electron effective mass are calculated. The obtained results are generally in good agreement with available experimental data. The gradient corrections to the local density approximation, included via generalized gradient approximation give significant improvement of the calculated pressure coefficients over the local density approximation.