We report converged quantum statistical mechanical simulations of liquid water with the TTM2.1-F, Thole-Type Model (version 2.1), Flexible, polarizable interaction potential for water [1]. The interaction potential has been parametrized from the results of high level electronic structure calculations for water clusters and has recently been parallelized to run efficiently on parallel architectures in both classical and quantum macroscopic simulations under periodic boundary conditions [2]. Quantum statistical (centroid molecular dynamics) simulations of total length of 600 ps with a 0.05 fs time step for a periodic unit cell of 256 molecules with up to 32 replicas per atom suggest that the quantum effects contribute 1.01±0.02 kcal/mol to the liquid enthalpy of formation at 298K. They furthermore demonstrate for the first time a quantitative agreement with experiment for the heights and broadening of the intramolecular OH and HH peaks in the radial distribution functions [3].

1. G. S. Fanourgakis and S. S. Xantheas, J. Phys. Chem. A 110, 4100 (2006).

2. G. S. Fanourgakis, V. Tipparaju, J. Nieplocha and S. S. Xantheas, Theor. Chem. Acc. 117, 73 (2007).

3. G. S. Fanourgakis, G. K. Schenter and S. S. Xantheas, J. Chem. Phys. 125, 141102 (2006).

^#This work was supported by the Division of Chemical Sciences, Geosciences and Biosciences, Office of Science, US Department of Energy. Battelle operates the Pacific Northwest National Laboratory for the US Department of Energy.

　代表的な界面活性剤のひとつであるドデシル硫酸ナトリウム(SDS)の球状ミセルに対し、分子動力学計算に基づく熱力学的積分法を用いて求めたミセルの生成自由エネルギーから、平均会合数やミセルサイズ分布について議論する。さらには、このような平均会合数やサイズ分布を与えるミセルの分子論について、安定構造の見地から詳細に検討する。