Ab initio quantum mechanical study of [gamma]-AlOOH Boehmite: structure and vibrational spectrum
MetadataShow full item record
The structure and vibrational spectrum of boehmite have been in- vestigated at the quantum-mechanical level with the CRYSTAL code, using a Gaussian-type basis set and the B3LYP Hamiltonian. Three space groups are considered in this study: Cmcm, Cmc21, P21/c. Cmcm turns out to corre- spond to a transition state, whereas Cmc21 and P21/c are minimum energy structures. The difference among them is the position of H atoms only, the Al-O frame being essentially the same. Harmonic frequencies at the ?? point have been computed. The comparison between calculated and experimental frequencies shows a good agreement for the Al-O part of the spectrum (under 790 cm-1). For the Al-OH bending modes (800-1300 cm-1) an absolute dif- ferences of 50-100 cm-1 is observed; for the OH stretching modes (3200-3500 cm-1) it increases to 120-200 cm-1: anharmonicity is large because OH groupsare involved in strong hydrogen bonds.
Showing items related by title, author, creator and subject.
The Gestalt of functioning in autism spectrum disorder: Results of the international conference to develop final consensus International Classification of Functioning, Disability and Health core setsBolte, Sven; Mahdi, S.; de Vries, P.; Granlund, M.; Robison, J.; Shulman, C.; Swedo, S.; Tonge, B.; Wong, V.; Zwaigenbaum, L.; Segerer, W.; Selb, M. (2018)Autism spectrum disorder is associated with diverse social, educational, and occupational challenges. To date, no standardized, internationally accepted tools exist to assess autism spectrum disorder–related functioning. ...
Radeloff, D.; Ciaramidaro, A.; Siniatchkin, M.; Hainz, D.; Schlitt, S.; Weber, B.; Poustka, F.; Bolte, Sven; Walter, H.; Freitag, C. (2014)© 2014 Radeloff et al. Autism spectrum disorder and schizophrenia share a substantial number of etiologic and phenotypic characteristics. Still, no direct comparison of both disorders has been performed to identify ...
Interplanetary scintillation studies with the Murchison Widefield Array III: Comparison of source counts and densities for radio sources and their sub-arcsecond components at 162MHzChhetri, Rajan; Ekers, Ronald; Morgan, John; Macquart, Jean-Pierre; Franzen, Thomas (2018)© 2018 The Author(s). We useMurchisonWidefieldArray(MWA) observations of interplanetary scintillation (IPS) to determine the source counts of point (< 0.3 arcsec extent) sources and of all sources with some subarcsecond ...