TIPS transferable intermolecular potential

Jorgensen and col. extended their TIPS (Transferable Intermolecular Potentials for Simulations) [120- 122] to several organic liquids. More recently, they developed a new generation of "effective" potentials, which received the denomination of OPLS (Optimized Potentials for Liquid Simulations) [123-127], The standard OPLS philosophy can be summarized in the following three points 1) to keep the form of the potentials simply and easy to evaluate, 2) to include as few new parameters as possible, 3) to produce structural and thermodynamic properties in reasonable accord with experiment. 

Water-water potential functions have been reported from different laboratories. The procedure leads either to analytic functions fitted to empirical data, e.g. SPC (single point charge) [19] and TIPS (transferable intermolecular potential functions)... 

The use of the HNC approximation to study the equilibrium properties of electrolytes and polar fluids is now widespread. Recent examples are the investigations of multipolar fluids by Fries and Patey (1985), the study of the TIPS (transferable intermolecular potentials) model for water and alkali halides in water by Pettitt and Rossky (1982, 1986), and a central-force model for water by Thuraisingham and Friedman (1983). Studies of the rod-like polyelectrolytes (Bacquet and Rossky, 1984) using the HNC approximation have shown qualitative agreement with Manning s (1969, 1978) counter-ion condensation theory, but some quantitative predictions of the theory are not borne out. In the section on WEAK ELECTROLYTES AND DIPOLAR DUMBBELLS, we discuss the sticky electrolyte model for weak electrolytes and acids, which has also been solved numerically in the HNC approximation (Rasaiah and Lee, 1985a). 

The parameters of five representative and commonly used water models in MD simulations are listed in Table 52.1. SPC is the short term for simple point charge, and SPC/E denotes the extended simple point charge model with charges on the oxygen and hydrogen modified to improve the classical SPC water model, the SPC/E model results in a better density and diffusion constant than the SPC model. TIP in TlPnP stands for transferable intermolecular potential, while nP means there are n points used in the corresponding water model. 

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