Octahedral tilting in cation-ordered perovskites - a group-theoretical approach
The perovskite (
ABX3) structure can be visualised as a three-dimensional network of regular corner-linked
BX6 octahedra, the
A cations being located in the cavities between them. Much of the structural variability arises from different patterns of
BX6 octahedral tilting. This paper deals with perovskites in which the octahedra contain two types of cation, in ordered arrangements, at stoichiometries
A3BBʹ2X9 and
A4BBʹ3X12. Group-theoretical methods are used to derive details of the structures obtained when this cation ordering occurs in combination with octahedral tilting.
C.J. Howard and H.T. Stokes