Materials Data on ErTl2P2Se7 by Materials Project
ErTl2P2Se7 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Er3+ is bonded in a 7-coordinate geometry to seven Se2- atoms. There are a spread of Er–Se bond distances ranging from 2.90–3.13 Å. There are two inequivalent Tl1+ sites. In the first Tl1+ site, Tl1+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Tl–Se bond distances ranging from 3.26–3.91 Å. In the second Tl1+ site, Tl1+ is bonded in a distorted q6 geometry to nine Se2- atoms. There are a spread of Tl–Se bond distances ranging from 3.35–3.74 Å. There are two inequivalent P+4.50+ sites. In the first P+4.50+ site, P+4.50+ is bonded in a tetrahedral geometry to four Se2- atoms. There are a spread of P–Se bond distances ranging from 2.22–2.25 Å. In the second P+4.50+ site, P+4.50+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are a spread of P–Se bond distances ranging from 2.18–2.22 Å. There are seven inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 2-coordinate geometry to one Er3+, three Tl1+, and one P+4.50+ atom. In the second Se2- site, Se2- is bonded in a distorted single-bond geometry to three Tl1+ and one P+4.50+ atom. In the third Se2- site, Se2- is bonded in a 2-coordinate geometry to one Er3+, two equivalent Tl1+, and one P+4.50+ atom. In the fourth Se2- site, Se2- is bonded in a 4-coordinate geometry to one Er3+, two Tl1+, and one P+4.50+ atom. In the fifth Se2- site, Se2- is bonded in a 5-coordinate geometry to one Er3+, three Tl1+, and one P+4.50+ atom. In the sixth Se2- site, Se2- is bonded in a 4-coordinate geometry to two equivalent Er3+, one Tl1+, and one P+4.50+ atom. In the seventh Se2- site, Se2- is bonded in a 2-coordinate geometry to one Er3+, three equivalent Tl1+, and one P+4.50+ atom.