Neutron diffraction structure determination of NaAlD4

The structure of NaAlD4 has been determined from Rietveld-type refinements of powder neutron diffraction data at 8 and 295 K. The space group is I4(1) la with a = 501.19(l) and c = 1131.47(5) pm at 295 K. The Na atoms are surrounded by eight D atoms from eight different [AlD4](-) tetrahedra in the geometry of a distorted square antiprism. The two different Na-D distances are nearly equal: 240.3(2) and 240.5(2) pm at 8 K and 243.1(2) and 243.9(2) pm at 295 K. The Al-D distance is 162.7(2) and 162.6(2) pm at 8 and 295 K, respectively. (C) 2003 Elsevier B.V. All rights reserved.