Self diffusion of water molecules simulated by model inter-atomic potentials determined by a combination of first-principles calculation and multi-canonical ensembles: exchange-correlation functional dependence

Water is an ubiquitous substance and is both scientifically and technologically important. In this study, the self diffusion of water molecules are simulated using Kumagai-Kawamura-Yokokawa type inter-atomic potentials [1] whose parameters are determined by a combination of first-principles calculation and multi-canonical ensembles [2,3]. Because of the property of multi-canonical ensemble, the determined potentials keep the thermodynamics of the reference first-principles simulations to a maximum extent. The author used PBE, PBE0, B3LYP, and B3LYP with DFT-D3 exchange-correlation potentials for the reference first-principles calculations to determine the model parameters. The obtained diffusion coefficients significantly depend on the choice of the exchange correlation functionals and the combination of B3LYP and DFT-D3 [4] produced the best agreement with the experimental one. \\[4pt] [1] N. Kumagai and K. Kawamura and T. Yokokawa, Mol. Simul. 12, 177 (1994).\\[0pt] [2] Y. Yoshimoto, J. Chem. Phys., 125, 184103 (2006).\\[0pt] [3] Y. Yoshimoto, J. Phys. Soc. Jpn., 79, 034602 (2010).\\[0pt] [4] S. Grimme, J. Antony, S. Ehrlich and H. Krieg, J. Chem. Phys, 132, 154104 (2010).