DOE OSTI2020
RbSbSe2 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded to seven Se2- atoms to form a mixture of distorted edge and corner-sharing RbSe7 pentagonal bipyramids. There are a spread of Rb–Se bond distances ranging from 3.51–3.83 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 3.44–3.96 Å. In the third Rb1+ site, Rb1+ is bonded to seven Se2- atoms to form a mixture of distorted edge and corner-sharing RbSe7 pentagonal bipyramids. There are a spread of Rb–Se bond distances ranging from 3.49–3.85 Å. In the fourth 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 3.45–3.88 Å. There are four inequivalent Sb3+ sites. In the first Sb3+ site, Sb3+ is bonded in a see-saw-like geometry to four Se2- atoms. There are a spread of Sb–Se bond distances ranging from 2.57–3.16 Å. In the second Sb3+ site, Sb3+ is bonded in a see-saw-like geometry to four Se2- atoms. There are a spread of Sb–Se bond distances ranging from 2.60–2.96 Å. In the third Sb3+ site, Sb3+ is bonded in a see-saw-like geometry to four Se2- atoms. There are a spread of Sb–Se bond distances ranging from 2.59–3.00 Å. In the fourth Sb3+ site, Sb3+ is bonded in a see-saw-like geometry to four Se2- atoms. There are a spread of Sb–Se bond distances ranging from 2.57–3.13 Å. There are eight inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 6-coordinate geometry to four Rb1+ and two Sb3+ atoms. In the second Se2- site, Se2- is bonded in a 6-coordinate geometry to four Rb1+ and two Sb3+ atoms. In the third Se2- site, Se2- is bonded in a 5-coordinate geometry to three Rb1+ and two Sb3+ atoms. In the fourth Se2- site, Se2- is bonded to four Rb1+ and two Sb3+ atoms to form distorted SeRb4Sb2 octahedra that share corners with two equivalent SeRb4Sb2 octahedra, a cornercorner with one SeRb3Sb2 trigonal bipyramid, edges with three equivalent SeRb4Sb2 octahedra, and edges with two equivalent SeRb3Sb2 trigonal bipyramids. The corner-sharing octahedral tilt angles are 17°. In the fifth Se2- site, Se2- is bonded in a 5-coordinate geometry to three Rb1+ and two Sb3+ atoms. In the sixth Se2- site, Se2- is bonded to four Rb1+ and two Sb3+ atoms to form distorted SeRb4Sb2 octahedra that share corners with two equivalent SeRb4Sb2 octahedra, a cornercorner with one SeRb3Sb2 trigonal bipyramid, edges with three equivalent SeRb4Sb2 octahedra, and edges with two equivalent SeRb3Sb2 trigonal bipyramids. The corner-sharing octahedral tilt angles are 16°. In the seventh Se2- site, Se2- is bonded to three Rb1+ and two Sb3+ atoms to form distorted SeRb3Sb2 trigonal bipyramids that share a cornercorner with one SeRb4Sb2 octahedra, corners with two equivalent SeRb3Sb2 trigonal bipyramids, edges with two equivalent SeRb4Sb2 octahedra, and an edgeedge with one SeRb3Sb2 trigonal bipyramid. The corner-sharing octahedral tilt angles are 58°. In the eighth Se2- site, Se2- is bonded to three Rb1+ and two Sb3+ atoms to form distorted SeRb3Sb2 trigonal bipyramids that share a cornercorner with one SeRb4Sb2 octahedra, corners with two equivalent SeRb3Sb2 trigonal bipyramids, edges with two equivalent SeRb4Sb2 octahedra, and an edgeedge with one SeRb3Sb2 trigonal bipyramid. The corner-sharing octahedral tilt angles are 59°.