Electronic structure study regarding the influence of macroscopic deformations on the vacancy formation energy in aluminum

We study the effect of macroscopic deformations on the vacancy formation energy in aluminum using electronic structure calculations based on orbital-free density functional theory. Specifically, working in the finite-deformation setting, we systematically traverse the six-dimensional strain space and calculate the corresponding vacancy formation energy. We find that the vacancy formation energy is primarily influenced by the volumetric component of strain, demonstrating a power law dependence; the defect core energy has a large variation with respect to the strain; and apart from the case of large tensile strains, the core energy is the main contributor to the vacancy formation energy. This demonstrates the importance of accounting for the defect core in continuum formulations, wherein it is typically neglected.