DOE OSTI2020
Rb2Cd2(SO4)3 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are four inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded in a 3-coordinate geometry to eleven O2- atoms. There are a spread of Rb–O bond distances ranging from 2.98–3.49 Å. In the second Rb1+ site, Rb1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Rb–O bond distances ranging from 2.87–3.38 Å. In the third Rb1+ site, Rb1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Rb–O bond distances ranging from 2.93–3.14 Å. In the fourth Rb1+ site, Rb1+ is bonded in a 8-coordinate geometry to ten O2- atoms. There are a spread of Rb–O bond distances ranging from 2.91–3.54 Å. There are four inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded to six O2- atoms to form distorted CdO6 octahedra that share corners with four SO4 tetrahedra. There are a spread of Cd–O bond distances ranging from 2.29–2.51 Å. In the second Cd2+ site, Cd2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Cd–O bond distances ranging from 2.20–2.40 Å. In the third Cd2+ site, Cd2+ is bonded to five O2- atoms to form distorted CdO5 square pyramids that share corners with three SO4 tetrahedra. There are a spread of Cd–O bond distances ranging from 2.19–2.35 Å. In the fourth Cd2+ site, Cd2+ is bonded to six O2- atoms to form distorted CdO6 octahedra that share corners with four SO4 tetrahedra. There are a spread of Cd–O bond distances ranging from 2.21–2.49 Å. There are six inequivalent S6+ sites. In the first S6+ site, S6+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of S–O bond distances ranging from 1.50–1.69 Å. In the second S6+ site, S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share a cornercorner with one CdO6 octahedra and a cornercorner with one CdO5 square pyramid. The corner-sharing octahedral tilt angles are 27°. There are a spread of S–O bond distances ranging from 1.48–1.51 Å. In the third S6+ site, S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share corners with three CdO6 octahedra and a cornercorner with one CdO5 square pyramid. The corner-sharing octahedra tilt angles range from 5–46°. There are a spread of S–O bond distances ranging from 1.48–1.50 Å. In the fourth S6+ site, S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share corners with two CdO6 octahedra and a cornercorner with one CdO5 square pyramid. The corner-sharing octahedra tilt angles range from 22–55°. There is one shorter (1.47 Å) and three longer (1.50 Å) S–O bond length. In the fifth S6+ site, S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share corners with two CdO6 octahedra. The corner-sharing octahedra tilt angles range from 26–42°. There are a spread of S–O bond distances ranging from 1.46–1.61 Å. In the sixth S6+ site, S6+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of S–O bond distances ranging from 1.53–1.56 Å. There are twenty-four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two Rb1+, one Cd2+, and one S6+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two Rb1+, one Cd2+, and one S6+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to two Rb1+, one Cd2+, and one S6+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cd2+ and one S6+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to two Rb1+, one Cd2+, and one S6+ atom. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to two Rb1+, one Cd2+, and one S6+ atom. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to two Rb1+, one Cd2+, and one S6+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to two Rb1+, one Cd2+, and one S6+ atom. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to one Rb1+, one Cd2+, and one S6+ atom. In the tenth O2- site, O2- is bonded in a distorted single-bond geometry to one Rb1+, one S6+, and one O2- atom. The O–O bond length is 1.48 Å. In the eleventh O2- site, O2- is bonded in a 2-coordinate geometry to two Rb1+, one Cd2+, and one S6+ atom. In the twelfth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Rb1+, one Cd2+, and one S6+ atom. In the thirteenth O2- site, O2- is bonded in a 1-coordinate geometry to one Rb1+, one Cd2+, and one S6+ atom. In the fourteenth O2- site, O2- is bonded in a 1-coordinate geometry to two Rb1+, one Cd2+, and one S6+ atom. In the fifteenth O2- site, O2- is bonded in a 1-coordinate geometry to one Rb1+, one Cd2+, and one S6+ atom. In the sixteenth O2- site, O2- is bonded in a distorted single-bond geometry to one Rb1+, one S6+, and one O2- atom. The O–O bond length is 1.49 Å. In the seventeenth O2- site, O2- is bonded in a 4-coordinate geometry to two Rb1+, one Cd2+, and one O2- atom. In the eighteenth O2- site, O2- is bonded in a 1-coordinate geometry to one Rb1+, one Cd2+, and one S6+ atom. In the nineteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Rb1+, one Cd2+, and one S6+ atom. In the twentieth O2- site, O2- is bonded in a 4-coordinate geometry to two Rb1+, one Cd2+, and one O2- atom. In the twenty-first O2- site, O2- is bonded in a 2-coordinate geometry to two Rb1+, one Cd2+, and one S6+ atom. In the twenty-second O2- site, O2- is bonded in a 1-coordinate geometry to one Rb1+, one Cd2+, and one S6+ atom. In the twenty-third O2- site, O2- is bonded in a distorted single-bond geometry to three Rb1+, one Cd2+, and one S6+ atom. In the twenty-fourth O2- site, O2- is bonded in a 1-coordinate geometry to one Rb1+, one Cd2+, and one S6+ atom.