First-principles calculations based upon density functional theory permitted the quantification the thermal equilibrium concentration of a point defect through calculating the formation energy of the defect. In order to know the formation energy, 3 parameters were needed: the energy difference between defective and perfect systems, chemical potential of constitutive atoms and Fermi level. The energy difference was obtained from calculations based upon “super-cell method”. The energy of a super-cell with a charged defect should be corrected by an appropriate way such as alignment of electrostatic potential. The chemical potential and Fermi level could be fixed from conditions of phase equilibrium and charge neutrality.

Theoretical Investigation to Thermal Equilibrium Concentration of Point Defect through First-Principles Calculation. A.Kuwabara: Science and Technology of Advanced Materials, 2007, 8[6], 519-23