Wyllieite-type Ag(1.09)Mn(3.46)(AsO(4))(3).

Single crystals of wyllieite-type silver(I) manganese(II) tris-orthoarsenate(V), Ag(1.09)Mn(3.46)(AsO(4))(3), were grown by a solid-state reaction. The three-dimensional framework is made up from four Mn(2+)/Mn(3+) cations surrounded octa-hedrally by O atoms. The MnO(6) octa-hedra are linked through edge- and corner-sharing. Three independent AsO(4) tetra-hedra are linked to the framework through common corners, delimiting channels along [100] in which two partly occupied Ag(+) sites reside, one on an inversion centre and with an occupancy of 0.631 (4), the other on a general site and with an occupancy of 0.774 (3), both within distorted tetra-hedral environments. One of the Mn sites is also located on an inversion centre and is partly occupied, with an occupancy of 0.916 (5). Related compounds with alluaudite-type or rosemaryite-type structures are compared and discussed.