title: Na4.25Mo15S19: a novel ternary reduced molybdenum sulfide containing Mo6 and Mo9 clusters.
abstract: The structure of tetra-sodium penta-deca-molybdenum nona-deca-sulfide, Na4.25Mo15S19, is isotypic with Na3.9Mo15Se19 [Salloum et al. (2013 ▶). Acta Cryst. E69, i67-i68]. It is characterized by Mo6S (i) 8S (a) 6 and Mo9S (i) 11S (a) 6 (where i represents inner and a apical atoms) cluster units that are present in a 1:1 ratio. The cluster units are centered at Wyckoff positions 2b and 2c, and have point-group symmetry -3 and -6, respectively. The clusters are inter-connected through additional Mo-S bonds. The Na(+) cations occupy inter-unit voids formed by six or seven S atoms. One Mo, one S and one Na site [occupancy 0.751 (12)] are situated on mirror planes, and two other S atoms and one Na site (full occupancy) are situated on threefold rotation axes.
authors.affiliation: Faculty of Science III, Lebanese University, PO Box 826, Kobbeh-Tripoli, Lebanon.
authors.forename: D
authors.initials: D
authors.lastname: Salloum
authors.affiliation: Unité Sciences Chimiques de Rennes, UMR CNRS No. 6226, Université de Rennes I - INSA Rennes, Campus de Beaulieu, 35042 Rennes Cedex, France.
authors.forename: P
authors.initials: P
authors.lastname: Gougeon
authors.affiliation: Unité Sciences Chimiques de Rennes, UMR CNRS No. 6226, Université de Rennes I - INSA Rennes, Campus de Beaulieu, 35042 Rennes Cedex, France.
authors.forename: P
authors.initials: P
authors.lastname: Gall