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Authors
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Friedel, P. ; Bergmann, J. ; Kleeberg, R. ; Schubert, G.
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Title
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A proposition for the structure of ammonium hydrogen (acid) urate from uroliths
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Date
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01.01.2006
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Number
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12583
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Abstract
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From naturally formed ammonium hydrogen urate, a common compound in uroliths, X-ray powder diffraction measurements, indexing and force-field-constrained Rietveld refinement including anisotropic characterization of peak width broadening were performed using the BGMN[tm] program. The ammonium hydrogen (acid) urate crystallizes in a triclinic unit cell with a = 0:3650 (3), b = 1:0215 (4), c = 1:0597 (5) nm, a = 113:9 (1), ß = 91:1(1) and · = 92:3(1)°. The symmetry was determined as P 1 (Space group No. 2). The agreement factor Rwp could be obtained to 7:43%. Inside the unit cell an additional ammonia molecule was placed with a probability of pNH3 = 0:34. This reduced occupancy and the anisotropic peak width hint to structural gradient related to the varying conditions of formation.
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Publisher
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Zeitschrift für Kristallographie
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Wikidata
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Citation
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Zeitschrift für Kristallographie 23 (2006) 517-522
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DOI
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https://doi.org/10.1524/zksu.2006.suppl_23.517
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Tags
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