Structural phase transformation of GaN under high-pressure: an exact exchange study

The phase transformation of GaN under high pressure is theoretically studied in the KS-DFT framework using the EXX method. Both KLI and LDA pseudopotentials were tried. The LDA-PP result for the transition pressure is 41.7 GPa while that of the KLI-PP is 41.5 GPa. Both results are in a very good agreement with the latest experimental value of 42 GPa. The effect of the nonlinear core correction is found to be small but not negligible.