Novel comparison of crystal packing by moments of inertia

Abstract

A new method is presented to compare crystal packing based on moments of inertia tensors. The approach allows any two crystal structures to be compared irrespective of chemical connectivity. Moreover, the strictly real-space method offers significant ease of interpretation of structural comparisons. The approach allows packing similarity to be identified in otherwise disparate compounds and has the potential to lead to new insight into the influences driving molecular aggregation, crystallisation and polymorphism. The packing relationships between several examples from the Cambridge Structural Database are discussed.