Molecular dynamics simulations of fluid XXXX properties using ab initio intermolecular interaction potentials.

@entity3884 @entity4885 @entity577 @entity74 @entity505
Intermolecular interaction energy data for the @entity577 dimer have been calculated at a spectroscopic accuracy and employed to construct an ab initio potential energy surface (PES) for @entity74 ( @entity74 ) simulations of fluid @entity577 properties. The full potential curves of the @entity577 dimer at 12 symmetric conformations were calculated by the supermolecule counterpoise-corrected second-order M  ller-Plesset ( @entity4885 ) perturbation theory. Single-point coupled cluster with single and double and perturbative triple excitations [CCSD(T)] calculations were also carried out to calibrate the @entity4885 potentials. We employed Pople's medium size basis sets [up to 6-311++G(3df, 3pd)] and Dunning's correlation consistent basis sets (cc-pVXZ and aug-cc-pVXZ, X = D, T, Q). For each conformer, the intermolecular @entity505 - @entity505 separation was sampled in a step 0.1 A for a range of 3-9 A, resulting in a total of 732 configuration points calculated. The @entity4885 binding curves display significant anisotropy with respect to the relative orientations of the dimer. The potential curves at the complete basis set (CBS) limit were estimated using well-established analytical extrapolation schemes. A 4-site potential model with sites located at the @entity3884 atoms was used to fit the ab initio potential data. This model stems from a @entity3884 - @entity3884 repulsion mechanism to explain the stability of the dimer structure. @entity74 simulations using the ab initio PES show quantitative agreements on both the atom-wise radial distribution functions and the self-diffusion coefficients over a wide range of experimental conditions.
