where µ i is the chemical potential of component i; A is the Helmholtz free energy; G is the Gibbs free energy; N j, j =i is the number of molecules of each component in the mixture; V is the volume of the system; T its temperature; and P its pressure. Calculations from systems under constant V and T yield A; G is obtained from simulations under constant P and T conditions. In order to estimate the chemical potential of one component in solution and in its molecular solid, however, we need to know the absolute free energy of the system in these states. We calcu-lated absolute free energies using alchemical free energy calculations.