DOE OSTI2020
Sc2Se3 crystallizes in the triclinic P1 space group. The structure is two-dimensional and consists of one Sc2Se3 sheet oriented in the (1, -1, 1) direction. there are four inequivalent Sc3+ sites. In the first Sc3+ site, Sc3+ is bonded in a 4-coordinate geometry to one Sc3+ and four Se2- atoms. The Sc–Sc bond length is 2.24 Å. There are a spread of Sc–Se bond distances ranging from 2.26–2.50 Å. In the second Sc3+ site, Sc3+ is bonded in a 4-coordinate geometry to one Sc3+ and four Se2- atoms. The Sc–Sc bond length is 2.24 Å. There are a spread of Sc–Se bond distances ranging from 2.23–2.50 Å. In the third Sc3+ site, Sc3+ is bonded in a 2-coordinate geometry to one Sc3+ and four Se2- atoms. There are a spread of Sc–Se bond distances ranging from 2.20–2.56 Å. In the fourth Sc3+ site, Sc3+ is bonded in a 2-coordinate geometry to one Sc3+ and four Se2- atoms. There are a spread of Sc–Se bond distances ranging from 2.21–2.58 Å. There are six inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 2-coordinate geometry to two Sc3+ and one Se2- atom. The Se–Se bond length is 2.21 Å. In the second Se2- site, Se2- is bonded in a 2-coordinate geometry to two Sc3+ and one Se2- atom. The Se–Se bond length is 2.20 Å. In the third Se2- site, Se2- is bonded in a 6-coordinate geometry to four Sc3+ and two Se2- atoms. In the fourth Se2- site, Se2- is bonded in a 2-coordinate geometry to three Sc3+ and two Se2- atoms. There are one shorter (2.21 Å) and one longer (2.29 Å) Se–Se bond lengths. In the fifth Se2- site, Se2- is bonded in a 2-coordinate geometry to three Sc3+ and two Se2- atoms. The Se–Se bond length is 2.29 Å. In the sixth Se2- site, Se2- is bonded in a distorted linear geometry to two Sc3+ and two Se2- atoms.