Materials Data on K(GeSe2)2 by Materials Project

Abstract

K(GeSe2)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 7-coordinate geometry to seven Se2- atoms. There are a spread of K–Se bond distances ranging from 3.38–3.95 Å. In the second K1+ site, K1+ is bonded in a 7-coordinate geometry to seven Se2- atoms. There are a spread of K–Se bond distances ranging from 3.37–3.98 Å. There are four inequivalent Ge+3.50+ sites. In the first Ge+3.50+ site, Ge+3.50+ is bonded to four Se2- atoms to form a mixture of corner and edge-sharing GeSe4 tetrahedra. There are a spread of Ge–Se bond distances ranging from 2.38–2.47 Å. In the second Ge+3.50+ site, Ge+3.50+ is bonded to four Se2- atoms to form corner-sharing GeSe4 tetrahedra. There are a spread of Ge–Se bond distances ranging from 2.35–2.47 Å. In the third Ge+3.50+ site, Ge+3.50+ is bonded to four Se2- atoms to form a mixture of corner and edge-sharing GeSe4 tetrahedra. There are a spread of Ge–Se bond distances ranging from 2.40–2.46 Å. In the fourth Ge+3.50+ site, Ge+3.50+ is bonded to four Se2- atoms to form corner-sharing GeSe4 tetrahedra. There are two shorter (2.63 Å) and two longer (2.64 Å) Ge–Se bond lengths. There are eight inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 2-coordinate geometry to one K1+ and two Ge+3.50+ atoms. In the second Se2- site, Se2- is bonded in a 2-coordinate geometry to two K1+ and two Ge+3.50+ atoms. In the third Se2- site, Se2- is bonded in a 4-coordinate geometry to two K1+ and two Ge+3.50+ atoms. In the fourth Se2- site, Se2- is bonded in a 3-coordinate geometry to three K1+ and two Ge+3.50+ atoms. In the fifth Se2- site, Se2- is bonded in a distorted trigonal non-coplanar geometry to one K1+ and two Ge+3.50+ atoms. In the sixth Se2- site, Se2- is bonded in a 3-coordinate geometry to one K1+ and two Ge+3.50+ atoms. In the seventh Se2- site, Se2- is bonded in a 2-coordinate geometry to three equivalent K1+ and two Ge+3.50+ atoms. In the eighth Se2- site, Se2- is bonded in a 2-coordinate geometry to one K1+ and two Ge+3.50+ atoms.