Accurate energetic ranking of crystal structures is vital in CSP, as polymorphs are known to often differ by only a few kJ/mol. It is generally understood that a more accurate energy model leads to improved (i.e. lower) ranking of experimentally observed crystal structures, which in turn makes it easier to identify novel structures of interest . Given a crystal structure landscape with lattice energies calculated using a force field, the fragment-based model described here can be seen as one of the simplest initial improvements to the energy model, as energetically significant two-body force field interactions are replaced with a higher level of theory without any re-optimization of the geometry.