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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 42: Focus: Multiscale Simulations for Soft Matter: The Challenge of Dynamics (joint session CPP/DY, organized by CPP)

CPP 42.2: Talk

Wednesday, March 9, 2016, 15:15–15:30, H51

Benchmark of a Reparametrized OPLS Force Field for Chlorinated Hydrocarbons Using Molecular Dynamics Simulations — •Zhu Liu, Jakob Timmermann, Karsten Reuter, and Christoph Scheurer — Theoretical Chemistry, Technische Universität München

The dielectric permittivity sensitively reflects the unique microscopic characteristics of a material [1]. To our knowledge no flexible non-polarizable force field for chlorinated hydrocarbons reliably reproduces this important physical property. We address this situation by reparametrizing an OPLS-AA (Optimized Parameters for Liquid Simulations, All-Atom) force field [2] to optimize the description of dynamic and dielectric properties. Specifically, we refitted the torsional potential energy profile and the atomic partial charges for several molecules from this class to match quantum chemical data. We find the new parametrization to yield a range of physical properties (especially the dielectric constant, isothermal compressibility, and thermal expansion coefficient) in excellent agreement with experimental data for a range of chlorinated hydrocarbon solvents, in addition to getting the surface tension and heat capacity at least as well as the original OPLS-AA model.

[1] C.J.F. Böttcher, Theory of Electric Polarization, Vol. I: Dielectrics in Static Fields, Elsevier B.V., Amsterdam (1973).

[2] W.L. Jorgensen et al., Proc. Natl. Acad. Sci. 102, 6665 (2005).