A Bond-Bond Portable Approach to Intermolecular Interactions: Simulations for N-methylacetamide and Carbon Dioxide Dimers

In this paper we present two applications of a recently developed method for obtaining analytical potential energy surfaces describing the intermolecular interaction of pairs of molecules made up of three or more atoms. The method is based on an empirical formulation of the intermolecular terms of the potential based on the idea that pairwise interaction terms, usually appearing in the many-body expansion of the potential energy, must be referred to pairs of interacting centers (group of atoms and/or bonds) of the molecular monomers, rather than, as traditionally done, to atomic centers. Such representation is incorporated in a grid empowered molecular simulator and coupled with dynamical calculations to evaluate observable properties of a simple CO2 dimer and a more complex chemical system (the N-methylacetamide dimer).