The band structure of GaN

The band structure of GaN has been calculated from a muffin tin potential constructed from the atomic potentials of Herman and Skillman. It was found necessary to introduce a charge shift parameter which could only be obtained very roughly from first principles. The band structure was calculated from this potential by first constructing a square well pseudopotential and then using this in a large plane wave secular equation. For a suitable choice of the charge shift parameter the band structure obtained is in good agreement but substantially different and flatter than previously obtained band structures for GaN.