A commensurately modulated structure of parabutlerite, FeIIISO4(OH)·2H2O.
Acta Crystallogr B Struct Sci Cryst Eng Mater
; 73(Pt 5): 856-862, 2017 Oct 01.
Article
en En
| MEDLINE
| ID: mdl-28980989
ABSTRACT
Parabutlerite, orthorhombic FeIIISO4(OH)·2H2O, has been reinvestigated using single-crystal X-ray diffraction. The structure of parabutlerite is commensurately modulated, with a = 20.0789â
(8), b = 7.4024â
(7), c = 7.2294â
(15)â
Å and q = 0.4b*. The superstructure has been determined, using a superspace approach, as having the superspace group Pnma(0ß0)s0s and t0 = 1/20, and refined to R = 0.0295 for 2392 main reflections with I > 3σ(I). The structure consists of infinite chains of Fe octahedra that are linked via vertices (OH groups); these chains are encased from both sides by SO4 tetrahedra. The displacive modulation of atoms in parabutlerite is connected with a tilt of the chains around the b axis towards the adjacent chains due to the accommodation of an energetically more favorable hydrogen-bond geometry.
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01-internacional
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MEDLINE
Idioma:
En
Revista:
Acta Crystallogr B Struct Sci Cryst Eng Mater
Año:
2017
Tipo del documento:
Article
País de afiliación:
República Checa