The structure of acuminite, a strontium aluminium fluoride mineral
Abstract An X-ray diffraction study of single crystals of acuminite, a strontium aluminium fluoride mineral from Ivigtut, Greenland [SrAlF 4 (OH) · H 2 O, a = 13.223(1) Å, b = 5.175(1) Å, c = 14.251(1) Å, β = 111.61(2), C 2/ c , Z = 8, D m = 3.295 g cm −3 , D c = 3.305 g cm −3 ] used 2138 diffractio...
Published in: | Zeitschrift für Kristallographie - Crystalline Materials |
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Other Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Walter de Gruyter GmbH
1991
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Subjects: | |
Online Access: | http://dx.doi.org/10.1524/zkri.1991.194.3-4.221 https://www.degruyter.com/document/doi/10.1524/zkri.1991.194.3-4.221/xml https://www.degruyter.com/document/doi/10.1524/zkri.1991.194.3-4.221/pdf |
Summary: | Abstract An X-ray diffraction study of single crystals of acuminite, a strontium aluminium fluoride mineral from Ivigtut, Greenland [SrAlF 4 (OH) · H 2 O, a = 13.223(1) Å, b = 5.175(1) Å, c = 14.251(1) Å, β = 111.61(2), C 2/ c , Z = 8, D m = 3.295 g cm −3 , D c = 3.305 g cm −3 ] used 2138 diffraction intensities (CAD-4 diffractometer), and was refined to R (unweighted) = 0.069. The strontium ions are 9-coordinated to 7 fluoride ions and 2 water molecules, the aluminium ions have octahedral coordination, 4 fluoride ions and 2 hydroxyl ions. The structure of acuminite is compared with the structure of tikhoenkovite another modification of SrAlF 4 (OH) · H 2 O. |
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