Supergroups of space groups and their application to the prediction of structural phase transitions

Abstract

A systematic procedure for the determination of supergroups of space groups is developed and used for the search of pseudosymmetric structures within crystal structure databases. The method is applied to P212121 structures listed in the Inorganic Crystal Structure Database. A significant number of compounds with known phase transitions at high temperatures are clearly detected as pseudosymmetric with differences between the transformed and original structure lower than 1·0 Å. Taking this value as a threshold about 20 additional compounds are detected having a high probability of exhibiting a phase transition at higher temperatures.