First principles calculations of the ground state properties and structural phase transformation in YN

We have studied the structural and electronic properties of YN in rock salt (sodium chloride), caesium chloride, zinc blende and wurtzite structures using first-principles total energy calculations. Rock salt is the calculated ground state structure with a = 4.93 Angstrom, B-0 = 157 GPa. The experimental lattice constant is a = 4.877 Angstrom. There is an additional local minimum in the wurtzite structure with total energy 0.28 eV/unit cell higher. At high pressure (similar to138 GPa), our calculations predict a phase transformation from a NaCl to a CsCl structure.