In accordance with experimental crystallographic data, an alanine crystal was prepared for simulations. Given the chiral space group of alanine (P2 1 2 1 2 1 ), a periodic box of 12.073 × 12.342 × 11.57 Å was constructed containing 16 alanine molecules. The Ewald real-space cutoff was 7 Å, and the van der Waals cutoff was 7 Å for the hydrated phase and 5 Å for the crystalline phase.