Simple point charge potential

Alper H E and R M Levy 1989. Computer Simulations of the Dielectric Properties of Water - Studies of the Simple Point-Charge and Transferable Intermolecular Potential Models. Journal of Chemical Physics 91 1242-1251. 

More realistic treatment of the electrostatic interactions of the solvent can be made. The dipolar hard-sphere model is a simple representation of the polar nature of the solvent and has been adopted in studies of bulk electrolyte and electrolyte interfaces [35-39], Recently, it was found that this model gives rise to phase behavior that does not exist in experiments [40,41] and that the Stockmeyer potential [41,42] with soft cores should be better to avoid artifacts. Representation of higher-order multipoles are given in several popular models of water, namely, the simple point charge (SPC) model [43] and its extension (SPC/E) [44], the transferable interaction potential (T1PS)[45], and other central force models [46-48], Models have also been proposed to treat the polarizability of water [49],... 

Atomistic MD models can be extended to the coarse-grained level introduced in the previous section, which is determined by the dimension of the backbone chain and branch. For the precise description of water molecular behavior, simple point charge (SPC) model was adopted (Krishnan et al., 2001), which can be used to simulate complex composition systems and quantitatively express vibrational spectra of water molecules in vapor, liquid, and solid states. The six-parameter (Doh, o , fi, Lye, Lyy, and Lee) SPC potential used for the water molecules is shown in Equation (24) ... 

SPC/E Simple point charge, extended empirical water potential)... 

Equation of State of Supercooled Water Simulated Using the Extended Simple Point Charge Intermolecular Potential. 

Harrington, P.H. Poole, F. Sciortino and H.E. Stanley, Equation of state of supercooled water simulated using the extended simple point charge intermolecular potential, J. Chem. Phys., 107 (1997) 7443-7450. 

SPC In view of the importance of the water-protein interactions it is of utmost interest to have available intermolecular potential functions for the water dimer that yield a good model for liquid water. The simple point charge (SPC) is a three-point charge (on the hydrogen and oxygen positions) model for water... 

Most nonpolarizable water models are actually fragile in this regard they are not transferable to temperatures or densities far from where they were parameterized.190 Because of the emphasis on transferability, polarizable models are typically held to a higher standard and are expected to reproduce monomer and dimer properties for which nonpolarizable liquid-state models are known to fail. Consequently, several of the early attempts at polarizable models were in fact less successful at ambient conditions than the benchmark nonpolarizable models, SPC191 (simple point charge) and TIP4P192 (transferable interaction potential, 4 points). Nonetheless, there is now a large collection of models that reproduce many properties of both the gas phase... 

Let us consider Met-enkephalin (Tyr-Gly-Gly-Phe-Met) with 75 atomic sites in three different solvents including water. The model of a wee ter molecule is the extended simple point charge (SPG/E) model [19]. It is assumed that the peptide is immersed in the solvent at infinite dilution. The potential-energy functions and parameters are adopted from KONF90 [20] that is based on ECEPP/2 [21]. The peptide and solvent molecules comprise the interaction sites (atoms). The interaction between the peptide molecule and a water molecule is expressed as the sum of the site-site pair interactions that have the form... 

---