I am looking for a proper way to describe distortions of coordination polyhedra. It is quite easy to find in the crystallographic literature a number of recipes for the calculation of quantitative parameters of distortion calculated from bond angles and distances, e.g. the popular bond angle variance and mean quadratic elongation of Robinson et al.. However, I was not able to find a QUALITATIVE classification of the various ways to distort the polyhedra, allowing for easy and unambiguous assignment of descriptions. In many papers the authors use name-like descriptions for the particular kind of distortion observed in their structure. However, it is normally not clear whether the names used are part of a general naming scheme of just made up by the authors or in a previous article on the structure.

As ideal, simple coordination polyhedra are platonic solids I suspect that any systematic work on the fundamental way to distort them might be quite old.