Abstract
The title compound displays isolated [SiS4]4− tetrahedra and a chain of I atoms along [001]. Iodine, which lies on a twofold axis, is coordinated by three lanthanum cations, one of which lies on the same twofold axis, forming an isosceles triangle. The compound is isotypic with Ce3I[SiS4]2 [Gauthier et al. (1998). J. Alloys Compd, 275–277, 46–49].