• Lattice energy. Lattice energy calculations were performed with an anisotropic atom-atom potential using DMACRYS . Electrostatic interactions were modelled using an atomic multipole description of the molecular charge distribution (up to hexadecapole on all atoms) from the B3LYP/6-311G(d,p)calculated charge density using a distributed multipole analysis . Atom-atom repulsion and dispersion interactions were modelled using a revised Williams intermolecular potential , which has been benchmarked against accurate, experimentally determined lattice energies for a range of molecular crystals .