Materials Data on Sm4Si2Se3O7 by Materials Project
Sm4Si2Se3O7 crystallizes in the tetragonal I4_1/amd space group. The structure is three-dimensional. there are two inequivalent Sm3+ sites. In the first Sm3+ site, Sm3+ is bonded in a 9-coordinate geometry to three Se2- and six O2- atoms. There are one shorter (2.95 Å) and two longer (2.99 Å) Sm–Se bond lengths. There are four shorter (2.49 Å) and two longer (2.64 Å) Sm–O bond lengths. In the second Sm3+ site, Sm3+ is bonded in a 6-coordinate geometry to three Se2- and three O2- atoms. There are one shorter (2.95 Å) and two longer (2.97 Å) Sm–Se bond lengths. There are one shorter (2.36 Å) and two longer (2.48 Å) Sm–O bond lengths. Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There is three shorter (1.65 Å) and one longer (1.66 Å) Si–O bond length. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 4-coordinate geometry to four equivalent Sm3+ and twelve O2- atoms. There are eight shorter (3.26 Å) and four longer (3.35 Å) Se–O bond lengths. In the second Se2- site, Se2- is bonded in a 6-coordinate geometry to four equivalent Sm3+ and two equivalent O2- atoms. Both Se–O bond lengths are 3.35 Å. In the third Se2- site, Se2- is bonded in a 4-coordinate geometry to four Sm3+ atoms. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Si4+ and one Se2- atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to three Sm3+, one Si4+, and one Se2- atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to three Sm3+, one Si4+, and one Se2- atom.