A transferable electrostatic model for intermolecular interactions between polycyclic aromatic hydrocarbons

This work builds on our recently published anisotropic potential for polycyclic aromatic hydrocarbons (PAH) [T.S. Totton, A.J. Misquitta, M. Kraft, J. Chem. Theory Comput. 6 (2010) 683] by developing a new transferable electrostatic model for PAH molecules. Using this model, the atomic charge parameters used in the PAH anisotropic potential may be rapidly calculated from a set of predefined parameters rather than from molecule-specific ab initio calculations. The importance of the out-of-the-plane quadrupolar moments is highlighted and they are used as the basis for an accurate and transferable electrostatic model for PAHs. This model exhibits an r.m.s. deviation of 1.7 kJ mol - 1 - an order of magnitude less than previous models.