In:
Zeitschrift für Kristallographie - Crystalline Materials, Walter de Gruyter GmbH, Vol. 233, No. 3-4 ( 2018-3-28), p. 279-284
Abstract:
The crystal structure of semseyite, Pb 9 Sb 8 S 21 was successfully refined using a single-crystal specimen from Wolfsberg, Harz, Germany, having chemical composition (EPMA) Pb 9.01(1) Sb 8.00(3) S 21.05(5) . The structure belongs to the monoclinic C 2/ c space group ( a =13.6267(10) Å, b =11.9742(9) Å, c =24.5891(18) Å, β =105.997(3)°, V =3856.8(5) Å 3 , Z =4, D c =6.048 g/cm 3 ). Crystal structure refinement with all atoms refined anisotropically converged to R 1 =4.64% (I 〉 2σ(I)). The crystal structure is built of two subunits (A and B) showing TlSbS 2 -like topology. Each of them stacks parallel to (001), and c /2 in thickness. Two cation sites (Pb1 and Sb5) located at central part of the subunit, show mixed occupancy behavior as 95% Pb and 5% Sb at the Pb5 site, and 95% Sb and 5% Pb at the Sb1 site, respectively. Each of subunits are related by unit cell-level twinning mechanism “tropochemical cell twinning” with the TlSbS 2 -like subunits alternatively parallel to (1 1 −4) and (−1 1 4) planes.
Type of Medium:
Online Resource
ISSN:
2196-7105
,
2194-4946
DOI:
10.1515/zkri-2017-2108
Language:
English
Publisher:
Walter de Gruyter GmbH
Publication Date:
2018
SSG:
13
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