Structure and energy of the 90° partial dislocation in diamond:: A combined ab initio and elasticity theory analysis

The core structure and stability of the 90 degrees partial dislocation in diamond is studied within isotropic elasticity theory and nb initio total energy calculations. The double-period reconstruction is found to be more stable than the single-period reconstruction for a broad range of stress states. The analysis of the ab initio results shows further that elasticity theory is valid for dislocation spacings as small as 10-20 Angstrom, thus allowing ab initio calculations to provide reliable parameters for continuum theory analysis.