Publication Date:
2016-09-24
Description:
The crystal structure of gianellaite, [(NHg 2 ) 2 ](SO 4 )(H 2 O) x , cubic, F 3 m , a = 9.521(6) Å V = 863.1(1.6) Å 3 , Z = 4, was solved by direct methods and refined to an R 1 index of 2.1% based on 167 unique observed reflections collected on a three-circle rotating-anode (Mo K α X-radiation) diffractometer equipped with multilayer optics and an APEX-II detector. In the structure of gianellaite, nitrogen-centred (NHg 4 ) 5+ tetrahedra share all corners to form a framework of tetrahedra with an ordered arrangement of interstitial (SO 4 ) 2– tetrahedra that show strong orientational disorder. Infrared spectroscopy in the principal O–H stretching region shows peaks at ~3300 and 1600 cm –1 , indicating the presence of (H 2 O), the position(s) of which could not be discerned in difference-Fourier maps.
Print ISSN:
0026-461X
Electronic ISSN:
1471-8022
Topics:
Geosciences
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