Redetermination of durangite, NaAl(AsO4)F
The crystal structure of durangite, ideally NaAl(AsO4)F (chemical name sodium aluminium arsenate fluoride), has been determined previously [Kokkoros (1938). Z. Kristallogr. 99, 38–49] using Weissenberg film data without reporting displacement parameters of atoms or a reliability factor. This study r...
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International Union of Crystallography
2012
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| Online Access: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3515088/ |
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pubmed-35150882013-01-02 Redetermination of durangite, NaAl(AsO4)F Downs, Gordon W. Yang, Betty N. Thompson, Richard M. Wenz, Michelle D. Andrade, Marcelo B. Inorganic Papers The crystal structure of durangite, ideally NaAl(AsO4)F (chemical name sodium aluminium arsenate fluoride), has been determined previously [Kokkoros (1938). Z. Kristallogr. 99, 38–49] using Weissenberg film data without reporting displacement parameters of atoms or a reliability factor. This study reports the redetermination of the structure of durangite using single-crystal X-ray diffraction data from a natural sample with composition (Na0.95Li0.05)(Al0.91Fe3+ 0.07Mn3+ 0.02)(AsO4)(F0.73(OH)0.27) from the type locality, the Barranca mine, Coneto de Comonfort, Durango, Mexico. Durangite is isostructural with minerals of the titanite group in the space group C2/c. Its structure is characterized by kinked chains of corner-sharing AlO4F2 octahedra parallel to the c axis. These chains are cross-linked by isolated AsO4 tetrahedra, forming a three-dimensional framework. The Na+ cation (site symmetry 2) occupies the interstitial sites and is coordinated by one F− and six O2− anions. The AlO4F2 octahedron has symmetry -1; it is flattened, with the Al—F bond length [1.8457 (4) Å] shorter than the Al—O bond lengths [1.8913 (8) and 1.9002 (9) Å]. Examination of the Raman spectra for arsenate minerals in the titanite group reveals that the position of the band originating from the As—O symmetric stretching vibrations shifts to lower wavenumbers from durangite, maxwellite [ideally NaFe(AsO4)F], to tilasite [CaMg(AsO4)F]. International Union of Crystallography 2012-10-27 /pmc/articles/PMC3515088/ /pubmed/23284315 http://dx.doi.org/10.1107/S160053681204384X Text en © Downs et al. 2012 http://creativecommons.org/licenses/by/2.0/uk/ This is an open-access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited. |
| repository_type |
Open Access Journal |
| institution_category |
Foreign Institution |
| institution |
US National Center for Biotechnology Information |
| building |
NCBI PubMed |
| collection |
Online Access |
| language |
English |
| format |
Online |
| author |
Downs, Gordon W. Yang, Betty N. Thompson, Richard M. Wenz, Michelle D. Andrade, Marcelo B. |
| spellingShingle |
Downs, Gordon W. Yang, Betty N. Thompson, Richard M. Wenz, Michelle D. Andrade, Marcelo B. Redetermination of durangite, NaAl(AsO4)F |
| author_facet |
Downs, Gordon W. Yang, Betty N. Thompson, Richard M. Wenz, Michelle D. Andrade, Marcelo B. |
| author_sort |
Downs, Gordon W. |
| title |
Redetermination of durangite, NaAl(AsO4)F |
| title_short |
Redetermination of durangite, NaAl(AsO4)F |
| title_full |
Redetermination of durangite, NaAl(AsO4)F |
| title_fullStr |
Redetermination of durangite, NaAl(AsO4)F |
| title_full_unstemmed |
Redetermination of durangite, NaAl(AsO4)F |
| title_sort |
redetermination of durangite, naal(aso4)f |
| description |
The crystal structure of durangite, ideally NaAl(AsO4)F (chemical name sodium aluminium arsenate fluoride), has been determined previously [Kokkoros (1938). Z. Kristallogr.
99, 38–49] using Weissenberg film data without reporting displacement parameters of atoms or a reliability factor. This study reports the redetermination of the structure of durangite using single-crystal X-ray diffraction data from a natural sample with composition (Na0.95Li0.05)(Al0.91Fe3+
0.07Mn3+
0.02)(AsO4)(F0.73(OH)0.27) from the type locality, the Barranca mine, Coneto de Comonfort, Durango, Mexico. Durangite is isostructural with minerals of the titanite group in the space group C2/c. Its structure is characterized by kinked chains of corner-sharing AlO4F2 octahedra parallel to the c axis. These chains are cross-linked by isolated AsO4 tetrahedra, forming a three-dimensional framework. The Na+ cation (site symmetry 2) occupies the interstitial sites and is coordinated by one F− and six O2− anions. The AlO4F2 octahedron has symmetry -1; it is flattened, with the Al—F bond length [1.8457 (4) Å] shorter than the Al—O bond lengths [1.8913 (8) and 1.9002 (9) Å]. Examination of the Raman spectra for arsenate minerals in the titanite group reveals that the position of the band originating from the As—O symmetric stretching vibrations shifts to lower wavenumbers from durangite, maxwellite [ideally NaFe(AsO4)F], to tilasite [CaMg(AsO4)F]. |
| publisher |
International Union of Crystallography |
| publishDate |
2012 |
| url |
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3515088/ |
| _version_ |
1611938235057963008 |