title: "NaB15": a new structural description based on X-ray and neutron diffraction, electron microscopy, and solid-state NMR spectroscopy
abstract: A boron-rich sodium boride, formerly known as NaB15, has been subjected to a comprehensive structural reinvestigation using X-ray single-crystal and powder diffraction, low-temperature neutron and electron diffraction, high-resolution transmission electron microscopy, and 23Na solid-state NMR spectroscopy. The results indicate that the previously published orthorhombic space group is incorrect. Consistent with all of the experimental results a modified structural description is developed in the monoclinic space group Ilml (a = 585.92(3), b= 1039.92(6), c = 833.17(5) pin, beta = 90.373(5) from powder data). Because one of the interstitial boron atom positions remains unoccupied, the accurate compositional formula is NaB145 or Na2B29.
authors.affiliation: Institut fur Anorganische und Analytische Chemie I, Justus-Liebig-Universitat, Giessen, Germany. barbara.albert@anorg.chemie.uni-giessen.de
authors.initials: B
authors.lastname: Albert
authors.initials: K
authors.lastname: Hofmann
authors.initials: C
authors.lastname: Fild
authors.initials: H
authors.lastname: Eckert
authors.initials: M
authors.lastname: Schleifer
authors.initials: R
authors.lastname: Gruehn