  We study the formation energies of native point defects in GaN through
density-functional theory. In our first-principles scheme, the band edges are
positioned in accord with hybrid density functional calculations, thus yielding
a band-gap in agreement with experiment. With respect to previous semilocal
calculations, the calculated formation energies and charge transition levels
are found to be significantly different in quantitative terms, while the
overall qualitative trend remains similar. In Ga-rich conditions, the nitrogen
vacancy corresponds to the most stable defect for all Fermi energies in the
band gap, but its formation energy is too high to account for autodoping. Our
calculations also indicate that the gallium vacancy does not play any
compensating role in n-type GaN.
