The inherent displacive structural flexibility of MxV2O5 framework structures

A Rigid Unit Mode (RUM) approach is used to investigate the inherent displa cive structural flexibility of layered and tunnel MxV2O5 framework structur es. Characteristic low energy modes of distortion of these framework struct ures are identified which do not distort the essentially rigid constituent polyhedral units and which enable the framework structures to respond to th e local crystal chemistry i.e. to the presence (or absence), as well as pos itioning, of a range of intercalating cations.