Structure and Energy of the 90 degree sign Partial Dislocation in Diamond: A Combined Ab Initio and Elasticity Theory Analysis

The core structure and stability of the 90 degree sign partial dislocation in diamond is studied within isotropic elasticity theory and ab 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. (c) 2000 The American Physical Society.