The inherent displacive structural flexibility of M(x)V₂O₅ framework structures

A Rigid Unit Mode (RUM) approach is used to investigate the inherent displacive structural flexibility of layered and tunnel M(x)V₂O₅ framework structures. Characteristic low energy modes of distortion of these frame-work structures are identified which do not distort the essentially rigid constituent polyhedral units and which enable the framework structures to respond to the local crystal chemistry i.e. to the presence (or absence), as well as positioning, of a range of intercalating cations.