Na(3)DyCl(6).

Single crystals of the title compound, tris-odium hexa-chloridodysprosate, Na(3)DyCl(6), were obtained as a by-product of synthesis using dysprosium(III) chloride and sodium chloride among others. The monoclinic structure with its typical β angle close to 90° [90.823 (4)°] is isotypic with the mineral cryolite (Na(3)AlF(6)) and the high-temperature structure of the Na(3)MCl(6) series, with M = Eu-Lu, Y and Sc. The isolated, almost perfect DyCl(6) octa-hedra are inter-connected via two crystallographically different Na(+) cations: while one Na(+) resides on centres of symmetry (as well as Dy(3+)) and also builds almost perfect, isolated NaCl(6) octa-hedra, the other Na(+) is surrounded by seven chloride anions forming a distorted NaCl(7) trigonal prism with just one cap as close secondary contact.