Materials Data on K2(TcSe2)3 by Materials Project
K2(TcSe2)3 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are three inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 6-coordinate geometry to six Se2- atoms. There are a spread of K–Se bond distances ranging from 3.30–3.67 Å. In the second K1+ site, K1+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of K–Se bond distances ranging from 3.32–3.61 Å. In the third K1+ site, K1+ is bonded in a 7-coordinate geometry to eight Se2- atoms. There are a spread of K–Se bond distances ranging from 3.24–3.89 Å. There are three inequivalent Tc+3.33+ sites. In the first Tc+3.33+ site, Tc+3.33+ is bonded to five Se2- atoms to form edge-sharing TcSe5 square pyramids. There are a spread of Tc–Se bond distances ranging from 2.51–2.63 Å. In the second Tc+3.33+ site, Tc+3.33+ is bonded to five Se2- atoms to form a mixture of corner and edge-sharing TcSe5 square pyramids. There are a spread of Tc–Se bond distances ranging from 2.50–2.68 Å. In the third Tc+3.33+ site, Tc+3.33+ is bonded to five Se2- atoms to form a mixture of corner and edge-sharing TcSe5 square pyramids. There are a spread of Tc–Se bond distances ranging from 2.50–2.68 Å. There are six inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 4-coordinate geometry to two K1+ and three Tc+3.33+ atoms. In the second Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent K1+ and three Tc+3.33+ atoms. In the third Se2- site, Se2- is bonded in a 5-coordinate geometry to two K1+ and three Tc+3.33+ atoms. In the fourth Se2- site, Se2- is bonded in a 6-coordinate geometry to three K1+ and three Tc+3.33+ atoms. In the fifth Se2- site, Se2- is bonded in a 5-coordinate geometry to three K1+, one Tc+3.33+, and one Se2- atom. The Se–Se bond length is 2.45 Å. In the sixth Se2- site, Se2- is bonded in a 5-coordinate geometry to three K1+ and two Tc+3.33+ atoms.