A semi-empirical electrostatic potential in the studies of molecular crystals Original Research Article

A model based on incorporation of the external electrostatic potential into a semi-empirical Hamiltonian has been applied to explore the effect of crystal packing on the electronic structure of molecules within crystals. Different schemes for representation of charge distribution within a molecule are compared. The results obtained using this model were compared to the results of calculations carried out with the COSMO method. The effect of electrostatic potential is subject to wide variations, depending on the packing motif, and it may exceed the effect of very polar solvents. For three pairs of polymorphs, the incorporation of electrostatic potential into the INDO/S scheme allowed the rationalization of their difference in color.