The structure of the lithium inserted metal oxide deltaLiV (2)0(5).

The case of lithium insertion into V(2)0(5) is of interest from both electrochemical and structural points of view. This reaction forms part of the basis for the discharge of Li/V (2)0(5) primary cells which are of commercial importance. Structually the V(2)0(5) host is unusual and displays the properties of both a layered compound and a crystallographic shear structure. Employing neutron and X-ray diffraction data and a diverse number of (unconventional) data analysis techniques, we have determined the crystal structure of LiV(2)0(5) and found that the V(2)0(5) undergoes significant structural distortion, involving the slipping of large layers of the host, to accommodate the lithium in sites of appropriate geometry. Remarkably, the V(2)0(5) host returns to its original structure on removal of the lithium.