The repulsion/dispersion component is inherently empirical and accounts predominantly for interactions arising from Pauli-exclusion and electron correlation. Due to its empirical nature, U r/d implicitly contains other residual binding forces such as polarisation, charge transfer, or electrostatic penetration effects that might be present in the reference data, but are less straightforward to model directly and hence are not explicitly included elsewhere in the model. The repulsion/dispersion term is often the leading contribution to lattice stability when considering van der Waals bound structures, although the electrostatic contribution can dominate for systems containing hydrogen bonds or ionic species. In this paper, the electrostatic term is modelled through the interactions of atom-centred point-charges or distributed multipoles. To mitigate issues related to conditional convergence , an Ewald summation is employed to evaluate the electrostatic term for all multipole ranks.