Computational study of stacking faults in sapphire using total energy methods

The structures and energetics of stacking faults on the prism planes in sapphire are studied computationally using total energy methods. Both first principles methods and empirical potentials are used to study four competing stacking fault structures on {1 (1) over bar 00} and one structure on {11 (2) over bar0}. Estimates for the vibrational contribution to the fault energy are obtained using empirical shell-model potentials. The calculated stacking fault energies are combined with anisotropic elasticity theory to predict the structure of low-angle symmetric tilt boundaries.