Received 25 January 2008
The crystal structure of the mineral lautite (copper arsenic sulfide), CuAsS, previously described as either centrosymmetric [Pnma; Marumo & Nowacki (1964). Schweiz. Miner. Petro. Mitt. 44, 439-454] or noncentrosymmetric [Pna21; Craig & Stephenson (1965). Acta Cryst. 19, 543-547], was reinvestigated by means of single-crystal X-ray diffraction. The centrosymmetric structural model reported previously was confirmed, although with improved precision for the atomic coordinates and interatomic distances. Lautite shows a sphalerite-derivative structure with a linking of Cu[AsS3], As[CuAs2S] and S[Cu3As] tetrahedra. All atoms lie on special positions (Wyckoff position 4c, site symmetry m).
Data collection: XSCANS (Bruker, 1997); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Xtaldraw (Downs & Hall-Wallace, 2003); software used to prepare material for publication: SHELXL97.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: FI2059 ).
This work was funded by CNR, Istituto di Geoscienze e Georisorse, Sezione di Firenze.
Bruker (1997). XSCANS. Bruker AXS Inc., Madison, Wisconsin, USA.
Craig, D. C. & Stephenson, N. C. (1965). Acta Cryst. 19, 543-547.
Downs, R. T. & Hall-Wallace, M. (2003). Am. Mineral. 88, 247-250.
Marumo, F. & Nowacki, W. (1964). Schweiz. Miner. Petro. Mitt. 44, 439-454.
North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351-359.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.
Wyckoff, R. W. G. (1963). Crystal Structures, 2nd ed. New York: Interscience Publishers.