Here, we chose three systems to study: An argon crystal for some small initial tests, α-methanol to help establish our protocol, and acetylsalicylic acid (ASA) as our main object of study. ASA is a known anti-inflammatory whose most stable polymorph, form I , has an aqueous solubility of approximately 0.038 % mole fraction at 298 K . We also used α-methanol at 150 K and a toy facecentered cubic (fcc) argon crystal to help us find an optimal protocol to calculate the absolute free energy of a molecular solid. α-methanol was chosen because it had been used before in a study which applied the EMM to calculate the absolute free energy of the solid .