An interatomic potential study of the properties of gallium nitride

A set of interatomic pair potentials were derived for gallium nitride within the shell-model approach. It was shown that the potential set successfully reproduces the properties of the fourfold-coordinated wurtzite and zinc-blende structures as well as the sixfold-coordinated rocksalt structure. The high-pressure phase transition from wurtzite to rock-salt structure is correctly described yielding the phase transition pressure of 50 GPa. The calculated formation energies of intrinsic point defects reveal that vacancies are the dominant native defects in GaN. Lastly,the calculated structure relaxation of the zinc-blende (110) surface predicts a layer rotation angle of 9 degrees in agreement with the results of recent first-principles calculations.