title: Structure and IR vibrational spectra of Na8[AlSiO4]6(BH4)2: comparison of theory and experiment.
abstract: The structure and IR vibrational spectra of tetrahydroborate sodalite (Na8[AlSiO4]6(BH4)2) were calculated using density functional theory (DFT) methods. The calculations, performed at the GGA hybrid DFT level yield a close agreement with XRD refinements of the structure and allow interpretation of observed bands of the enclosed BH4(–) and the framework and, in particular, a verification of hydrogen positions (Buhl, J.-C., Gesing, T. M., and Rüscher, C. H. Microporous Mesoporous Mater. 2005, 80, 57−63). In a first step, different basis sets and functionals were tested on NaBH4 and Na8[AlSiO4]6Cl2. We show that accurate treatment of B–H stretching modes requires anharmonic corrections, while lattice vibrations are well described within the harmonic approximation.
authors: Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms Universität Bonn , Beringstrasse 4-6, D-53115 Bonn, Germany.
authors: Alexander G
authors: AG
authors: Schneider
authors: Thomas
authors: T
authors: Bredow
authors: Lars
authors: L
authors: Schomborg
authors: Claus H
authors: CH
authors: Rüscher