Ab Initio Interaction Potentials for Simulations of Dimethylnitramine Solutions in Supercritical Carbon Dioxide with Cosolvents

Symmetry-adapted perturbation theory has been employed to calculate ab initio potential energy surfaces for complexes involved in the process of dissolving dimethylnitramine in supercritical carbon dioxide in the presence of acetonitrile or methyl alcohol as cosolvents. Site−site fits with correct asymptotic behavior have been developed for all potentials. The new potential energy surfaces can be used, along with the previously reported ones for carbon dioxide and carbon dioxide−acetonitrile dimers, in fully ab initio simulations of supercritical extraction processes. The physical interpretation of the features of the interaction potential energy surfaces resulting from the present approach challenges the established literature interpretations in terms of electrostatics only.