Theoretical study of the relative stability of wurtzite and rocksalt phases in MgO and GaN - art. no. 104103

We report local density functional calculations using the full-potential li nearized muffin-tin orbital method for MgO and GaN in the wurtzite and rock salt structures and for orthorhombic structures along a homogeneous strain transition path linking wurtzite to rocksalt. MgO is found to be unstable i n the wurtzite and marginally metastable in a layered hexagonal phase, labe led h-MgO, in which Mg is approximately fivefold coordinated, the stable ph ase being rocksalt. GaN is stable in the wurtzite at ambient pressures but exhibits a phase transition to the rocksalt. Band structures and charge den sities exhibiting the bond formation as one goes from one structure to the other are presented.