Abstract
Symmetry corrections are added to a structural optimization at constant pressure in order to preserve the symmetry during the numerical relaxation of a structure. The enthalpy is minimized as a function of the electronic structure, the metric , and the atomic positions. For the antiperovskite structures and the structural parameters and the band structure are calculated. The results are in good agreement with the available experimental data. For the pressure dependence of the structural parameters and of the band-gap energy is also discussed. A possible transition from the orthorhombic phase to an eightfold-coordinated cubic phase (SC15) is found at 59 GPa.
- Received 25 June 1997
DOI:https://doi.org/10.1103/PhysRevB.57.7615
©1998 American Physical Society