Deriving intermolecular potentials for predicting the crystal structures of polar molecules

We demonstrate the ability of an ab initio-based distributed-multipole model for the electrostatic contribution to the intermolecular potential, together with literature-based isotropic atom-atom repulsion-dispersion potentials, to model the crystal structures of polar organic molecules. This potential provides remarkably good structure predictions and so can be used as a benchmark and starting point for further optimization of the repulsion-dispersion potential parameters. Reducing the electrostatic contribution to the intermolecular potential, to counteract the overestimate of the molecular charge distribution due to the use of a self-consistent field wavefunction, produces improvements to the crystal structure predictions.