Materials Data on Pr2SmS4 by Materials Project
SmPr2S4 crystallizes in the tetragonal I-42d space group. The structure is three-dimensional. Sm2+ is bonded to eight equivalent S2- atoms to form distorted SmS8 hexagonal bipyramids that share corners with eight equivalent PrS8 hexagonal bipyramids, edges with four equivalent SmS8 hexagonal bipyramids, and faces with eight equivalent PrS8 hexagonal bipyramids. There are four shorter (2.87 Å) and four longer (3.05 Å) Sm–S bond lengths. Pr3+ is bonded to eight equivalent S2- atoms to form distorted PrS8 hexagonal bipyramids that share corners with four equivalent SmS8 hexagonal bipyramids, corners with four equivalent PrS8 hexagonal bipyramids, edges with four equivalent PrS8 hexagonal bipyramids, faces with four equivalent SmS8 hexagonal bipyramids, and faces with four equivalent PrS8 hexagonal bipyramids. There are a spread of Pr–S bond distances ranging from 2.89–3.07 Å. S2- is bonded to two equivalent Sm2+ and four equivalent Pr3+ atoms to form a mixture of distorted edge, corner, and face-sharing SPr4Sm2 octahedra. The corner-sharing octahedra tilt angles range from 17–50°.