First-principles calculations of the ground-state properties and stability of ScN

Using first-principles total-energy calculations, we have studied the structural and electronic properties of ScN in the rocksalt (sodium chloride), cesium chloride, nickel arsenide, zinc-blende, and wurtzite structures, Rocksalt is the calculated ground-state structure with a = 4.54 Angstrom, B-0 = 201 GPa. Experimental values are a = 4.501 Angstrom, B-0 = 182 +/- 40 GPa. There is an additional local minimum in the wurtzite structure. Its total energy is 0.34 eV/(unit formula) higher than the energy of the rocksalt structure. Since other group IIIA nitrides crystallize in the wurtzite structure, this result is important in the possible fabrication of Se-IIIA-N alloys. At very high pressure, our calculations show the possibility of a phase transition from the NaCl to a metallic CsCl structure.