  Applying external strain is an efficient way to manipulate the site
preference of dopants in semiconductors, however, the validity of the previous
continuum elastic model for the strain influence on the doping forma- tion
energy is still under debate. In this paper, by combining quantum mechanical
theoretical analysis and first-principles calculations, we show that if the
occupation change of different orbitals caused by the strain is negligible, the
continuum elastic model is valid, otherwise it will fail. Our theory is
confirmed by first-principles calculation of Mn-doped GaAs system. Moreover, we
show that under compressive strain the hole density, thus the Curie temperature
TC can increase in Mn-doped spintronic materials.
