Materials Data on Gd4Si2Se3O7 by Materials Project
Gd4Si2Se3O7 crystallizes in the tetragonal I4_1/amd space group. The structure is three-dimensional. there are two inequivalent Gd3+ sites. In the first Gd3+ site, Gd3+ is bonded in a 9-coordinate geometry to three Se2- and six O2- atoms. There are one shorter (2.93 Å) and two longer (2.97 Å) Gd–Se bond lengths. There are a spread of Gd–O bond distances ranging from 2.46–2.63 Å. In the second Gd3+ site, Gd3+ is bonded in a 6-coordinate geometry to three Se2- and three O2- atoms. There are one shorter (2.93 Å) and two longer (2.95 Å) Gd–Se bond lengths. There are one shorter (2.33 Å) and two longer (2.47 Å) Gd–O bond lengths. Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.64–1.66 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 4-coordinate geometry to four Gd3+ atoms. In the second Se2- site, Se2- is bonded in a 4-coordinate geometry to four equivalent Gd3+ and twelve O2- atoms. There are eight shorter (3.23 Å) and four longer (3.31 Å) Se–O bond lengths. In the third Se2- site, Se2- is bonded in a 6-coordinate geometry to four equivalent Gd3+ and two equivalent O2- atoms. Both Se–O bond lengths are 3.31 Å. 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 1-coordinate geometry to three Gd3+, one Si4+, and one Se2- atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Gd3+, one Si4+, and one Se2- atom.