Liquid properties of dimethyl ether from molecular dynamics simulations using<i>Ab Initio</i>force fields

Abstract

We have used molecular dynamic simulations to study the structural and dynamical properties of liquid dimethyl ether (DME) with a newly constructed ab initio force field in this article. The ab initio potential energy data were calculated at the second order Møller-Plesset (MP2) perturbation theory with Dunning's correlation consistent basis sets (up to aug-cc-pVQZ). We considered 17 configurations of the DME dime for the orientation sampling. The calculated MP2 potential data were used to construct a 3-site united atom force field model. The simulation results are compared with those using the empirical force field of Jorgensen and Ibrahim (Jorgensen and Ibrahim, J Am Chem Soc 1981, 103, 3976) and with available experimental measurements. We obtain quantitative agreements for the atom-wise radial distribution functions, the self-diffusion coefficients, and the shear viscosities over a wide range of experimental conditions. This force field thus provides a suitable starting point to predict liquid properties of DME from first principles intermolecular interactions with no empirical data input a priori.