Crystal structure of synthetic Pb4Bi12Se6.2S15.8

Abstract

The crystal structure of Pb4Bi12 Se6.2S15.8, Cmcm with a = 4.08424(10), b = 13.4273(3), c = 37.4761(8) Å, has been determined using 1120 unique intensity data with I > 3 σ(I) out of a total of 8735 independent reflections measured with a single crystal X-ray diffractometer. Charge balancing of the stoichiometry M16 X22 (M = Pb,Bi: X = S,Se) has determined the overall chemistry, with the above composition being obtained after refinement of the occupancies of the anion sites. The relationship of its structure to those of the lillianite family of structures and previously reported compounds in the PbS-Bi2S3 system is discussed.