Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (19) Citing Articles via Google Scholar Google Scholar Articles by Liu, Y. Articles by Nekvasil, H. Search for Related Content GeoRef GeoRef Citation

Si-F bonding in aluminosilicate glasses: Inferences from ab initio NMR calculations

Center for High Pressure Research and Department of Geosciences, State University of New York, Stony Brook, New York 11794-2100, U.S.A.

Correspondence: ^* E-mail: yunliu{at}ic.sunysb.edu

Although it has been well accepted that F-Al linkages dominate in F-bearing alkali aluminosilicate glasses, the possibility of F-Si linkages remains unresolved. Recent ¹⁹F NMR results have been interpreted as indicative of not only the presence of the Al-F-Na(n) linkages but also of the presence of Si-F-Na(n) linkages. High level ab initio NMR calculations were performed to investigate the nature of possible species contributing to the ¹⁹F spectra.

The B3LYP/6-31G* level was used to optimize structures and a scaling technique applied to the calculation of NMR properties using both HF and B3LYP methods at the 6-311+G(2df,p) level. The applicability of this scaling method was checked by comparing calculated results against experimental data on several crystalline materials; the results are improved over HF or DFT methods alone. The calculation results show that none of the F-Al species investigated can produce the –147 ppm peak of Schaller et al. (1992). However, several species in which F is bonded to fourfold-, fivefold-, and sixfold-coordinated Si produce a ¹⁹F chemical shift of approximately –147 ppm. These results verify the assignments of this peak by Zeng and Stebbins (2000) to tetrahedral Si-F and NaSiF₆-like species, and rule out many other possible species. Several additional species such as a fivefold coordinated Si-F species may further contribute to the –147 ppm ¹⁹F peak.

This article has been cited by other articles:

				F. Farges, R. L. Linnen, and G. E. Brown Jr. REDOX AND SPECIATION OF TIN IN HYDROUS SILICATE GLASSES: A COMPARISON WITH Nb, Ta, Mo AND W Can Mineral, June 1, 2006; 44(3): 795 - 810. [Abstract] [Full Text] [PDF]

				M. Zimova and S. Webb The effect of chlorine on the viscosity of Na2O-Fe2O3-Al2O3-SiO2 melts American Mineralogist, February 1, 2006; 91(2-3): 344 - 352. [Abstract] [Full Text] [PDF]