Computer simulation of trifluoromethane properties with ab initio force field

Abstract

Intermolecular interaction potentials of the trifluoromethane dimer in 15 orientations have been calculated using the Hartree-Fock (HF) self-consistent theory and the second-order Møller-Plesset (MP2) perturbation theory. Single point energies at important geometries were also calibrated by the coupled cluster with single and double and perturbative triple excitation [CCSD(T)] calculations. We have employed Pople's medium size basis sets [up to 6-311++G(3df,3pd)] and Dunning's correlation consistent basis sets (up to aug-cc-pVQZ). Basis set limit potential values were obtained through well-studied extrapolation methods. The calculated MP2 potential data were employed to parameterize a 5-site force field for molecular simulations. We performed molecular dynamics simulations using the constructed ab initio force field and compared the simulation results with experiments. Quantitative agreements for the atom-wise radial distribution functions and the self-diffusion coefficients over a wide range of experimental conditions can be obtained, thus validating the ab initio force field without using experimental data a priori.

Liquid properties of dimethyl ether from molecular dynamics simulations usingAb Initioforce fields

“…The MD simulations were performed using similar methodology as used before [13,14] with the program provided by Rapaport. [30] Basically, a total of 864 DME molecules were initially arranged randomly in a rectangular cell with the periodic boundary conditions imposed.…”

“…[13,14] Briefly, the potential data were calculated by using the Gaussian 03 program package. [15] The isolated DME molecule was optimized at the MP2/aug-cc-pVTZ level of theory and the optimized geometry has the C 2v symmetry.…”

Molecular Dynamics Simulations with ab Initio Force Fields: A Review of Case Studies on CH4, CCl4, CHF3, and CHCl3 Dimers

“…When two monomers approach each other, it depends on the relative orientation to form a stable molecular dimer (conformer). For sampling the directional responses we consider several dimer structures as shown in the respective papers [21][22][23][24]. We have used the MP2 method [26] to account for the correlation effect.…”

“…Therefore, we use the state-of-the-art methodology to obtain accurate potential energies for the studied dimers and then construct the globally smooth force fields for use in molecular dynamics simulations. In this review we present our recent efforts in constructing reliable ab initio force fields for use in molecular dynamics simulations [21][22][23][24]. We demonstrate the systematic scheme by using several case studies done in our group in the past decade.…”

Coarse-Grained Simulations Using a Multipolar Force Field Model

“…We evaluate the performance of the simulation results by directly comparing ab initio molecular dynamics simulations with experiments [17,18,19]. In this paper, we develop a systematic approach for the coarse-grained rigid blob (CGRB) models, which can provide a hierarchy of multiscale numerical tests.…”