2004/09/10 by D. R. Hamann, Xifan Wu, Karin M. Rabe +1 · 1 citation
Physics and Astronomy · #cond-mat.mtrl-sci #cond-mat.other
paper · pdf · doi:10.1103/physrevb.71.035117
25 pages, no figures, submitted to Phys. Rev. B
arxiv created 2004/09/10 · arxiv updated 2009/12/01
The direct calculation of the elastic and piezoelectric tensors of solids can be accomplished by treating homogeneous strain within the framework of density-functional perturbation theory. By formulating the energy functional in reduced coordinates, we show that the strain perturbation enters only through metric tensors, and can be treated in a manner exactly paralleling the treatment of other perturbations. We present an analysis of the strain perturbation of the plane-wave pseudopotential functional, including the internal strain terms necessary to treat the atomic-relaxation contributions. Procedures for computationally verifying these expressions by comparison with numerical derivatives of ground-state calculations are described and illustrated.