Abstract
The crystal structure of tris-odium potassium dodeca-molybdenum tetra-deca-sulfide, Na2.9 (2)KMo12S14, consists of Mo12S14S6 cluster units inter-connected through inter-unit Mo-S bonds and delimiting channels in which the Na(+) cations are disordered. The cluster units are centered at Wyckoff positions 2d and have point-group symmetry 3.2. The K atom lies on sites with 3.2 symmetry (Wyckoff site 2c) between two consecutive Mo12S14S6 units. One of the three independent S atoms and one Na atom lie on sites with 3.. symmetry (Wyckoff sites 4e and 4f). The other Na atom occupies a 2b position with -3.. symmetry. The crystal studied was a merohedral twin with refined components of 0.4951 (13) and 0.5049 (13).