AIMD-based training data were collected using the Vienna Ab initio Simulation Package (VASP), which uses the plane-wave basis functions with projector augmented-wave (PAW) pseudopotentials and the Perdew-Burke-Ernzerhof (PBE) exchange-correlation functional in the generalized gradient approximation. The numbers of explicit valence electrons used in the pseudopotentials were 1, 4, 6, and 9 for H, C, O, and Ho ions, respectively. For all ab initio calculations, the energy cutoff in the expansion of the plane waves was 400 eV, which was requested from the used pseudopotentials. The system was treated as an insulator; thus, the k-point smearing width was set to be small (0.01 eV).