The crystal structure of fedotovite, K2Cu30(SO4) 3

Abstract The crystal structure of fcdotovite, K1CU30(S04h has been determined, space group C2/e, a 19.037(6), h 9.479(2), e 14.231(5) A,~1 11.04(3t, Z = 8, Dx = 3.09 g/cm3. The main units of the fedotovite structure are formed around two additional oxygen atoms and consist of edge-sharing [OCU4J tetrahedra and four [S04J tetrahedra attached to them. The units are further connected by two [S04J tetrahedra, building distinct layers parallel to the yz plane. These layers are interconnected by potassium atoms. In the fedotovite structure, the three kinds of copper atoms are fivefold (4 + 1) coordinated to oxygen atoms with a strong Jahn-Teller effect. The coordination polyhedra of Cui and Cu2 atoms are distorted and flattened orthorhombic pyramids with Cu-O distances varying from 1.912 to 2.333 A,. the sixth neighbour of the both atoms is the copper atom lying at 2.975 and 2.981 Afor Cu2 and Cui respectively. The coordination environment of the Cu3 atom is a distorted elongated orthorhombic pyramid with four Cu-O distances from 1.943 to 1.961 A, a fifth at 2.558 A, and further sixth and seventh neighbours (oxygen and copper atoms) at 2.809 and 2.806 A, respectively