A method was demonstrated for carrying out first-principles free-energy calculations within the Kohn-Sham scheme. It was shown that the method could be used in cases where electrons had to be decoupled from the system, and it was illustrated by using results for the free energy of formation of the Si vacancy. The results agreed well with available data from experiments and  ab initio  calculations.

E.Smargiassi, R.Car: Physical Review B, 1996, 53[15], 9760-3