Materials Data on KCe5S8 by Materials Project
KCe5S8 crystallizes in the tetragonal I-4 space group. The structure is three-dimensional. K1+ is bonded to eight S2- atoms to form distorted KS8 hexagonal bipyramids that share corners with eight equivalent CeS8 hexagonal bipyramids, edges with four equivalent CeS8 hexagonal bipyramids, and faces with eight equivalent CeS8 hexagonal bipyramids. There are four shorter (3.02 Å) and four longer (3.17 Å) K–S bond lengths. There are two inequivalent Ce3+ sites. In the first Ce3+ site, Ce3+ is bonded to eight S2- atoms to form distorted CeS8 hexagonal bipyramids that share corners with two equivalent KS8 hexagonal bipyramids, corners with six CeS8 hexagonal bipyramids, edges with four equivalent CeS8 hexagonal bipyramids, faces with two equivalent KS8 hexagonal bipyramids, and faces with six CeS8 hexagonal bipyramids. There are a spread of Ce–S bond distances ranging from 2.83–3.14 Å. In the second Ce3+ site, Ce3+ is bonded to eight S2- atoms to form distorted CeS8 hexagonal bipyramids that share corners with eight equivalent CeS8 hexagonal bipyramids, edges with four equivalent KS8 hexagonal bipyramids, and faces with eight equivalent CeS8 hexagonal bipyramids. There are four shorter (2.87 Å) and four longer (3.03 Å) Ce–S bond lengths. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a 6-coordinate geometry to one K1+ and five Ce3+ atoms. In the second S2- site, S2- is bonded in a 6-coordinate geometry to one K1+ and five Ce3+ atoms.