AIMD simulations with a 1 × 1 × 1 k-point mesh were performed for a 1 × 1 × 2 supercell (512 atoms) generated from the optimized cell constants and atomic positions. An N V T ensemble (fixed volume and temperature control) with a 1-fs timestep was employed to obtain the equilibrium state and collect training data for the parameterization. The temperature was controlled using a Nosé-Hoover thermostat. The temperature was set to 153 K, which is the same as that used in SC-XRD analysis. AIMD calculations were performed for a 10-ps equilibrium run until the energy and temperature were stable. Subsequently, a production run and data sampling for the training data were performed for 200 fs with 20 step intervals. As a result, the forces, stresses, and energy for ten systems in total were prepared for the parameterization.