Materials Data on Cs2Sn4Se9O by Materials Project
Cs2Sn4Se9O crystallizes in the orthorhombic Pna2_1 space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 1-coordinate geometry to three Se+1.33- and one O2- atom. There are a spread of Cs–Se bond distances ranging from 3.71–3.75 Å. The Cs–O bond length is 3.19 Å. In the second Cs1+ site, Cs1+ is bonded in a 1-coordinate geometry to six Se+1.33- and one O2- atom. There are a spread of Cs–Se bond distances ranging from 3.62–4.28 Å. The Cs–O bond length is 3.37 Å. There are four inequivalent Sn3+ sites. In the first Sn3+ site, Sn3+ is bonded to five Se+1.33- atoms to form SnSe5 trigonal bipyramids that share a cornercorner with one SnSe4 tetrahedra, an edgeedge with one SnSe5 trigonal bipyramid, and an edgeedge with one SnSe4 trigonal pyramid. There are a spread of Sn–Se bond distances ranging from 2.60–2.90 Å. In the second Sn3+ site, Sn3+ is bonded to five Se+1.33- atoms to form SnSe5 trigonal bipyramids that share a cornercorner with one SnSe4 trigonal pyramid, an edgeedge with one SnSe4 tetrahedra, and an edgeedge with one SnSe5 trigonal bipyramid. There are a spread of Sn–Se bond distances ranging from 2.61–2.89 Å. In the third Sn3+ site, Sn3+ is bonded to four Se+1.33- atoms to form SnSe4 trigonal pyramids that share a cornercorner with one SnSe4 tetrahedra, a cornercorner with one SnSe5 trigonal bipyramid, and an edgeedge with one SnSe5 trigonal bipyramid. There are a spread of Sn–Se bond distances ranging from 2.53–2.63 Å. In the fourth Sn3+ site, Sn3+ is bonded to four Se+1.33- atoms to form SnSe4 tetrahedra that share a cornercorner with one SnSe5 trigonal bipyramid, a cornercorner with one SnSe4 trigonal pyramid, and an edgeedge with one SnSe5 trigonal bipyramid. There are a spread of Sn–Se bond distances ranging from 2.53–2.62 Å. There are nine inequivalent Se+1.33- sites. In the first Se+1.33- site, Se+1.33- is bonded in a 2-coordinate geometry to two Sn3+ atoms. In the second Se+1.33- site, Se+1.33- is bonded in a 2-coordinate geometry to two Sn3+ atoms. In the third Se+1.33- site, Se+1.33- is bonded in a 3-coordinate geometry to one Cs1+ and two Sn3+ atoms. In the fourth Se+1.33- site, Se+1.33- is bonded in a distorted rectangular see-saw-like geometry to two Cs1+ and two Sn3+ atoms. In the fifth Se+1.33- site, Se+1.33- is bonded in a 2-coordinate geometry to one Cs1+ and two Sn3+ atoms. In the sixth Se+1.33- site, Se+1.33- is bonded in a 4-coordinate geometry to two Cs1+ and two Sn3+ atoms. In the seventh Se+1.33- site, Se+1.33- is bonded in a 2-coordinate geometry to one Cs1+, two Sn3+, and one O2- atom. The Se–O bond length is 3.64 Å. In the eighth Se+1.33- site, Se+1.33- is bonded in a distorted L-shaped geometry to one Cs1+ and two Sn3+ atoms. In the ninth Se+1.33- site, Se+1.33- is bonded in a 3-coordinate geometry to one Cs1+ and two Sn3+ atoms. O2- is bonded in a distorted bent 120 degrees geometry to two Cs1+ and one Se+1.33- atom.