First-principles free-energy calculations on condensed-matter systems: Lattice vacancy in silicon

Abstract
We illustrate a method for performing first-principles free-energy calculations within the Kohn-Sham scheme. We show that the method can be used in cases in which electrons have to be decoupled from the system and illustrate it with results for the formation free energy of the Si vacancy. The results agree well with the available data from experiments and ab initio calculations. © 1996 The American Physical Society.