Materials Data on Sn4TeSe3 by Materials Project
(SnSe)2Sn2TeSe crystallizes in the monoclinic Pm space group. The structure is two-dimensional and consists of one Sn2TeSe sheet oriented in the (0, 0, 1) direction and one SnSe sheet oriented in the (0, 0, 1) direction. In the Sn2TeSe sheet, there are two inequivalent Sn2+ sites. In the first Sn2+ site, Sn2+ is bonded to four equivalent Te2- and one Se2- atom to form a mixture of distorted edge and corner-sharing SnTe4Se square pyramids. There are two shorter (2.96 Å) and two longer (3.43 Å) Sn–Te bond lengths. The Sn–Se bond length is 2.79 Å. In the second Sn2+ site, Sn2+ is bonded in a 3-coordinate geometry to one Te2- and two equivalent Se2- atoms. The Sn–Te bond length is 2.97 Å. Both Sn–Se bond lengths are 2.82 Å. Te2- is bonded in a 5-coordinate geometry to five Sn2+ atoms. Se2- is bonded in a trigonal non-coplanar geometry to three Sn2+ atoms. In the SnSe sheet, there are two inequivalent Sn2+ sites. In the first Sn2+ site, Sn2+ is bonded in a distorted T-shaped geometry to three Se2- atoms. There are one shorter (2.77 Å) and two longer (2.82 Å) Sn–Se bond lengths. In the second Sn2+ site, Sn2+ is bonded in a 3-coordinate geometry to three Se2- atoms. There are one shorter (2.78 Å) and two longer (2.82 Å) Sn–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a trigonal non-coplanar geometry to three Sn2+ atoms. In the second Se2- site, Se2- is bonded in a trigonal non-coplanar geometry to three Sn2+ atoms.