DOE OSTI2020
Rb(SnSe2)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Rb–Se bond distances ranging from 3.48–4.05 Å. In the second Rb1+ site, Rb1+ is bonded in a 7-coordinate geometry to seven Se2- atoms. There are a spread of Rb–Se bond distances ranging from 3.57–4.14 Å. There are four inequivalent Sn+3.50+ sites. In the first Sn+3.50+ site, Sn+3.50+ is bonded to four Se2- atoms to form a mixture of corner and edge-sharing SnSe4 tetrahedra. There are a spread of Sn–Se bond distances ranging from 2.50–2.61 Å. In the second Sn+3.50+ site, Sn+3.50+ is bonded to four Se2- atoms to form corner-sharing SnSe4 tetrahedra. There are a spread of Sn–Se bond distances ranging from 2.54–2.61 Å. In the third Sn+3.50+ site, Sn+3.50+ is bonded to four Se2- atoms to form a mixture of corner and edge-sharing SnSe4 tetrahedra. There are a spread of Sn–Se bond distances ranging from 2.48–2.63 Å. In the fourth Sn+3.50+ site, Sn+3.50+ is bonded in a distorted rectangular see-saw-like geometry to four Se2- atoms. There are a spread of Sn–Se bond distances ranging from 2.77–3.22 Å. There are eight inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 3-coordinate geometry to one Rb1+ and two Sn+3.50+ atoms. In the second Se2- site, Se2- is bonded in a 4-coordinate geometry to three Rb1+ and two Sn+3.50+ atoms. In the third Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to two Rb1+ and two Sn+3.50+ atoms. In the fourth Se2- site, Se2- is bonded in a 5-coordinate geometry to three equivalent Rb1+ and two Sn+3.50+ atoms. In the fifth Se2- site, Se2- is bonded in a 3-coordinate geometry to one Rb1+ and two Sn+3.50+ atoms. In the sixth Se2- site, Se2- is bonded in a 5-coordinate geometry to three Rb1+ and two Sn+3.50+ atoms. In the seventh Se2- site, Se2- is bonded in a distorted water-like geometry to one Rb1+ and two Sn+3.50+ atoms. In the eighth Se2- site, Se2- is bonded in a 2-coordinate geometry to one Rb1+ and two Sn+3.50+ atoms.