The crystal structure of caratiite

ABSTRACT. The crystal structure of caratiite, K4CU402 (S04)4MeCI (a 13.60(2), c 4.98(I)A, Z = 2) was solved in space group 14 from single crystal data, and refined to R = 0.035 for 654Fo > 6u(Fo). The atomic arrangement is characterized by CU20(S04)2 chains parallel to [001], with Cu in (4+ 1) co-ordination and°surrounded tetrahedrally by four Cu atoms. These chains are interconnected by K atoms to a framework, the channels of which house theMe and CI atoms. The nature of the Me atoms is not completely clear; most probably the position is half occupied by Cu, fully occupied by Na, or occupied by a mixture of the two