caa a22 4500 463217586 CHVBK 20180405153202.0 cr unu---uuuuu 170326e20070701xx s 000 0 eng 10.1007/s00269-007-0148-8 doi (NATIONALLICENCE)springer-10.1007/s00269-007-0148-8 Potential protonation sites in the Al2SiO5 polymorphs based on polarized FTIR spectroscopy and properties of the electron density distribution [Elektronische Daten] [Jason Burt, Nancy Ross, G. Gibbs, George Rossman, Kevin Rosso] Potential protonation sites for, kyanite, sillimanite, and andalusite, located in a mapping of the (3, −3) critical points displayed by their L(r)=−∇2ρ(r) distributions, are compared with polarized single-crystal FTIR spectra of kyanite and sillimanite determined earlier and with andalusite measured in this study. For andalusite, seven peaks were observed when the electric vector, E, is parallel to [100]: four intense ones at 3,440, 3,460, 3,526, and 3,597cm−1 and three weaker ones at 3,480, 3,520, and 3,653cm−1. Six peaks, three intense ones at 3,440, 3,460, and 3,526cm−1 and three weaker ones at 3,480, 3,520, and 3,653cm−1 when E parallels [010]. No peaks were observed when E is parallel to [001]. The concentration of water in andalusite varies between 110 and 168ppm by weight % H2O. Polarized FTIR spectra indicate that the OH vector is parallel to (001) in andalusite and sillimanite and $$ {\left( {11\ifmmode\expandafter\bar\else\expandafter\=\fi{1}} \right)} $$ in kyanite. Examination of the L(r) (3, −3) critical points in comparison with the polarized FTIR indicates that H prefers to bond to the oxygen atoms O1 and O2 in andalusite and O2 and O4 in sillimanite which correspond to the underbonded oxygen atoms and those with the largest L(r) maxima. In kyanite, comparison of the FTIR spectrum and the critical points indicates that H will preferentially bond to the two 4-coordinated O2 and O6 atoms. Springer-Verlag, 2007 FTIR nationallicence Hydrogen nationallicence (3, −3) critical points nationallicence Andalusite nationallicence Sillimanite nationallicence Kyanite nationallicence Burt Jason Department of Geosciences, University of Arizona, 85721, Tucson, AZ, USA aut Ross Nancy Department of Geosciences, Virginia Tech, 24061, Blacksburg, VA, USA aut Gibbs G. Departments of Geosciences, Materials Science and Engineering, and Mathematics, Virginia Tech, 24061, Blacksburg, VA, USA aut Rossman George Division of Geological and Planetary Sciences, California Institute of Technology, 91125-2550, Pasadena, CA, USA aut Rosso Kevin W. R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O. Box 999, 99352, Richland, WA, USA aut Physics and Chemistry of Minerals Springer-Verlag 34/5(2007-07-01), 295-306 0342-1791 34:5<295 2007 34 269 https://doi.org/10.1007/s00269-007-0148-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00269-007-0148-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Burt Jason Department of Geosciences, University of Arizona, 85721, Tucson, AZ, USA aut NATIONALLICENCE 700 1- Ross Nancy Department of Geosciences, Virginia Tech, 24061, Blacksburg, VA, USA aut NATIONALLICENCE 700 1- Gibbs G. Departments of Geosciences, Materials Science and Engineering, and Mathematics, Virginia Tech, 24061, Blacksburg, VA, USA aut NATIONALLICENCE 700 1- Rossman George Division of Geological and Planetary Sciences, California Institute of Technology, 91125-2550, Pasadena, CA, USA aut NATIONALLICENCE 700 1- Rosso Kevin W. R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O. Box 999, 99352, Richland, WA, USA aut NATIONALLICENCE 773 0- Physics and Chemistry of Minerals Springer-Verlag 34/5(2007-07-01), 295-306 0342-1791 34:5<295 2007 34 269 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer