Status of the Gaussian Electrostatic Model, a Density-Based Polarizable Force Field

Status of the Gaussian Electrostatic Model, a Density-Based Polarizable Force Field 

4 place Jussieu 75005, Paris, France CNRS, UMR 7616 Laboratoire de Chimie Theorique case courrier 137, 

The use of classical potentials for simulations of chemical and biochemical systems with molecular d3mamics has been a field of intense research. Currently, it is possible to simulate systems with millions of atoms and millisecond time scales (Schulten et al., 2008 Shaw et al., 2010). With exa-scale computing, i.e., 10 floating point operations per second (FLOPs), on the horizon it is necessary to evaluate the performance of the current potentials. Indeed, longtime biomolecular simulations have revealed some issues already. 

Many-Body Effects and Electrostatics in Biomolecules Edited by Qiang Cui, Markus Meuwly, and Pengyu Ren Copyright (c) 2016 Pan Stanford Publishing Pte. Ltd. 

In this contribution, we present the theory behind the GEM method and recent advances and results on the application of two hybrid GEM potentials. In Section 8.2, we provide a brief review of the analytical and numerical density fitting methods and its implementation, including the methods employed to control numerical instabilities. This is followed by a review of the procedure to obtain distributed site multipoles from the fitted Hermite coefficients in Section 8.3. Section 8.4 describes the extension of reciprocal space methods for continuous densities. Section 8.5 describes the complete form for GEM and a novel hybrid force field, GEM, which combines term from GEM and AMOEBA for MD simulations. Finally, Section 8.6 describes the implementation and initial applications of a multi-scale program that combines GEM and SIBFA. 

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