Materials Data on SmCuSe2 by Materials Project
SmCuSe2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Sm3+ is bonded to seven Se2- atoms to form distorted SmSe7 pentagonal bipyramids that share corners with four equivalent SmSe7 pentagonal bipyramids, corners with five equivalent CuSe4 tetrahedra, edges with seven equivalent SmSe7 pentagonal bipyramids, and edges with four equivalent CuSe4 tetrahedra. There are a spread of Sm–Se bond distances ranging from 2.92–3.22 Å. Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with five equivalent SmSe7 pentagonal bipyramids, corners with four equivalent CuSe4 tetrahedra, edges with four equivalent SmSe7 pentagonal bipyramids, and an edgeedge with one CuSe4 tetrahedra. There are a spread of Cu–Se bond distances ranging from 2.45–2.63 Å. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 5-coordinate geometry to four equivalent Sm3+ and one Cu1+ atom. In the second Se2- site, Se2- is bonded in a 6-coordinate geometry to three equivalent Sm3+ and three equivalent Cu1+ atoms.