Ladders of information: what contributes to the structural complexity of inorganic crystals.

Complexity is one of the important characteristics of crystal structures, which can be measured as the amount of Shannon information per atom or per unit cell. Since complexity may arise due to combination of different factors, herein we suggest a method of ladder diagrams for the analysis of contributions to structural complexity from different crystal-chemical phenomena (topological complexity, superstructures, modularity, hydration state, etc.). The group of minerals and inorganic compounds based upon the batagayite-type [M(TO4)Ï•] layers (M = Fe, Mg, Mn, Ni, Zn, Co; T = P, As; Ï• = OH, H2O) is used as an example. It is demonstrated that the method allows for the quantitative estimates of various contributions to the complexity of the whole structure. [ABSTRACT FROM AUTHOR]