Article
Sensitivity Analysis of Distribution Functions of Liquid Water
Journal of Chemical Physics
(1993)
Abstract
We have carried out sensitivity analysis studies to identify the most important potential parameters of the SPC and the TIP3P flexible water models in determining three distribution functions of liquid water—the site–site radial distribution functions, the distribution function of the interaction energy of a water molecule with its surrounding [Pu(ub)], and the distribution function of the local electric field at the oxygen of a water molecule projected along the permanent dipole moment vector of the water molecule [Pe(E⋅μ0)]. The site–site radial distribution functions of each water model are most sensitive to the equilibrium O–H bond length (rOH) and the Lennard‐Jones radius (σ) of the model. In addition to these two parameters, the cut‐off radius (Rcut) in the reaction field geometry and the atomic partial charges are also important in affecting Pu(ub) of each model, especially the wings of the distribution. The oxygen charge affects the low energy wing of Pu(ub) more than the high energy wing, whereas the hydrogen charge mainly affects the high energy wing and has little effect on the low energy wing of the distribution. As for Pe(E⋅μ0), which provides an indirect check of the validity of the effective charge approximation in accounting for molecular polarizability, the leading factors are rOH, σ, and Rcut. These parameters affect the distribution wings of Pe(E⋅μ0) the most. The key advantage of the sensitivity analysis technique is that it provides a systematic and economical means for studying the role of each parameter of a water model in affecting the properties of the model.
Disciplines
Publication Date
January 12, 1993
DOI
10.1063/1.465572
Citation Information
Sheng‐Bai Zhu and Chung F. Wong. "Sensitivity Analysis of Distribution Functions of Liquid Water" Journal of Chemical Physics Vol. 99 Iss. 11 (1993) p. 9047 - 9053 Available at: http://works.bepress.com/chung-wong/64/