Crystal structure of Nb2Te4O13

Nb2Te4O13 crystallises in the space group P1 with the unit cell parameters: a = 7.535(5) Angstrom, b = 12.647(7) Angstrom, c = 12.702(7) Angstrom, alp ha =116.05(4), beta = 90.15 (4), gamma = 90.03(4), Z = 4. Its structure has been refined by a full matrix least-squares process to R-1 = 0.029 and wR( 2) = 0.068 values on the basis of 5202 independent single crystal X-ray ref lections recorded with an automatic diffractometer. Infinite trans chains o f NbO6 octahedra are connected via TeO4 disphenoids and TeO3 pyramids, to f orm double UVO5 like-sheets. These sheets are cross-linked by beta-TeO2-lik e chains of alternately corner and edge-sharing TeO4 disphenoids, and consi tute a three dimensional network, in the tunnels of which are located the e lectronic lone pairs E of Te4+ cations. (C) 2000 Elsevier Science S.A. All rights reserved.