Elaboration, structural study and validation of a new NASICON-type structure, Na 0.72 (Cr 0.48 ,Al 1.52 )(Mo 2.77 ,Al 0.23 )O 12 .

The title compound, sodium chromium/aluminium molybdenum/aluminium dodeca-oxide, Na0.72 Cr0.48 Al1.74 Mo2.77 O12 , was prepared by solid-state reaction. Its crystal structure is related to NaSICON-type compounds. The framework is built up from M 1O6 ( M 1 = Cr/Al) octa-hedra and M 2O4 ( M 2 = Mo/Al) tetra-hedra inter-connected by corners. The three-dimensional framework contains cavities in which sodium cations are located. Two validation models (BVS and CHARDI) were used to confirm the proposed structural model. The mobility of Na+ ions in the structure has been investigated by theoretical means.