Diffusion constant of the TIP5P model of liquid water

The diffusion constant of TLP5P [J. Chem. Phys. 112, 8910 (2000)], the rece ntly developed five-site rigid nonpolarizable model of liquid water that si gnificantly improves the description of water's density anomaly, has been c alculated at a range of temperatures between -25 degreesC and 75 degreesC a nd pressures between 1 atm and 3000 atm. The diffusion constant, in units o f 10(-5) cm(2)/s, for TIP5P water at 25 degreesC and 1 atm is 2.62+/-0.04 a s compared with the experimental value of 2.30. This is a significant impro vement over most commonly used water models, e.g., for TIP4P and TIP3P [J. Chem. Phys. 79, 926 (1983)] the diffusion constants are 3.29+/-0.05 and 5.0 6+/-0.09, respectively, and for SPC it is 3.85+/-0.09. The diffusion consta nt of TIP5P decreases dramatically with decreasing temperature, as is obser ved experimentally, and the change in the diffusion constant as pressure is increased is also consistent with experimental results. (C) 2001 American Institute of Physics.