Energy-based model construction typically results in larger models as compared to algorithms implemented in the rinrus program, nevertheless the τ 2B models consistently deliver higher accuracy. Simple distancebased models with a 6 Å cutoff are also found to be effective. rinrus models could be further improved by including a coordination sphere in the seed moiety, but this would require users to know which residues are relevant. Alternatively, two-body semi-empirical calculations are affordable enough to be incorporated into model-building workflows and require no a priori information beyond a crystal structure.