Free-energy calculations in materials research

Various methods for calculating the free energies of fluids, solids, and discrete spin systems are reviewed with particular emphasis on applications relevant in materials science. First, traditional methodologies based on harmonic approximations and thermodynamic integration are examined to highlight the workings of these very useful and robust techniques. Several newer and more specialized strategies are then discussed to provide a snapshot of current practices. Our aim here is to compare and contrast several related techniques and to provide an assessment of their relative strengths.