The effect of impurities upon the basal-plane stacking-fault energy was investigated by using density functional theory. It was found that Si, In, Mg and C all reduced the stacking-fault energy by introducing changes into the bonding properties. The latter were analyzed in terms of Mulliken charges and bond populations. It was concluded that the reduction in stacking-fault energy was related to a reduction in the average anion charge and to an increase in the overlap population.

Ab initio Study of the Effect of Doping on Stacking Faults in GaN. J.A.Chisholm, P.D.Bristowe: Journal of Crystal Growth, 2001, 230[3-4], 432-7