TY - JOUR
T1 - Crystal structure of tetrawickmanite, Mn2+Sn4+(OH)6
AU - Lafuente, Barbara
AU - Yang, Hexiong
AU - Downs, Robert T.
AU - Weil, M.
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2015/2/1
Y1 - 2015/2/1
N2 - The crystal structure of tetrawickmanite, ideally Mn2+Sn4+(OH)6 [mangan-ese(II) tin(IV) hexahydroxide], has been determined based on single-crystal X-ray diffraction data collected from a natural sample from LÅngban, Sweden. Tetrawickmanite belongs to the octahedral-framework group of hydroxide-perovskite minerals, described by the general formula BB′(OH)6 with a perovskite derivative structure. The structure differs from that of an ABO3 perovskite in that the A site is empty while each O atom is bonded to an H atom. The perovskite B-type cations split into ordered B and B′ sites, which are occupied by Mn2+ and Sn4+, respectively. Tetrawickmanite exhibits tetragonal symmetry and is topologically similar to its cubic polymorph, wickmanite. The tetrawickmanite structure is characterized by a framework of alternating corner-linked [Mn2+(OH)6] and [Sn4+(OH)6] octahedra, both with point-group symmetry 1¯. Four of the five distinct H atoms in the structure are statistically disordered. The vacant A site is in a cavity in the centre of a distorted cube formed by eight octahedra at the corners. However, the hydrogen-atom positions and their hydrogen bonds are not equivalent in every cavity, resulting in two distinct environments. One of the cavities contains a ring of four hydrogen bonds, similar to that found in wickmanite, while the other cavity is more distorted and forms crankshaft-type chains of hydrogen bonds, as previously proposed for tetragonal stottite, Fe2+Ge4+(OH)6.
AB - The crystal structure of tetrawickmanite, ideally Mn2+Sn4+(OH)6 [mangan-ese(II) tin(IV) hexahydroxide], has been determined based on single-crystal X-ray diffraction data collected from a natural sample from LÅngban, Sweden. Tetrawickmanite belongs to the octahedral-framework group of hydroxide-perovskite minerals, described by the general formula BB′(OH)6 with a perovskite derivative structure. The structure differs from that of an ABO3 perovskite in that the A site is empty while each O atom is bonded to an H atom. The perovskite B-type cations split into ordered B and B′ sites, which are occupied by Mn2+ and Sn4+, respectively. Tetrawickmanite exhibits tetragonal symmetry and is topologically similar to its cubic polymorph, wickmanite. The tetrawickmanite structure is characterized by a framework of alternating corner-linked [Mn2+(OH)6] and [Sn4+(OH)6] octahedra, both with point-group symmetry 1¯. Four of the five distinct H atoms in the structure are statistically disordered. The vacant A site is in a cavity in the centre of a distorted cube formed by eight octahedra at the corners. However, the hydrogen-atom positions and their hydrogen bonds are not equivalent in every cavity, resulting in two distinct environments. One of the cavities contains a ring of four hydrogen bonds, similar to that found in wickmanite, while the other cavity is more distorted and forms crankshaft-type chains of hydrogen bonds, as previously proposed for tetragonal stottite, Fe2+Ge4+(OH)6.
KW - Crystal structure
KW - Mineral structure
KW - Polymorphism
KW - Tetrawickmanite
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U2 - 10.1107/S2056989015001632
DO - 10.1107/S2056989015001632
M3 - Article
AN - SCOPUS:84928164445
VL - 71
SP - 234
EP - 237
JO - Acta Crystallographica Section E: Structure Reports Online
JF - Acta Crystallographica Section E: Structure Reports Online
SN - 1600-5368
IS - 2
ER -