Materials Data on K4Nb2S11 by Materials Project
K4Nb2S11 crystallizes in the orthorhombic Pca2_1 space group. The structure is three-dimensional. there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 7-coordinate geometry to seven S+1.27- atoms. There are a spread of K–S bond distances ranging from 3.09–3.67 Å. In the second K1+ site, K1+ is bonded in a 8-coordinate geometry to eight S+1.27- atoms. There are a spread of K–S bond distances ranging from 3.31–3.67 Å. In the third K1+ site, K1+ is bonded in a 7-coordinate geometry to seven S+1.27- atoms. There are a spread of K–S bond distances ranging from 3.30–3.60 Å. In the fourth K1+ site, K1+ is bonded in a 9-coordinate geometry to nine S+1.27- atoms. There are a spread of K–S bond distances ranging from 3.29–3.72 Å. There are two inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded in a 7-coordinate geometry to seven S+1.27- atoms. There are a spread of Nb–S bond distances ranging from 2.26–2.86 Å. In the second Nb5+ site, Nb5+ is bonded in a 7-coordinate geometry to seven S+1.27- atoms. There are a spread of Nb–S bond distances ranging from 2.26–2.87 Å. There are eleven inequivalent S+1.27- sites. In the first S+1.27- site, S+1.27- is bonded in a 1-coordinate geometry to four K1+, one Nb5+, and one S+1.27- atom. The S–S bond length is 2.08 Å. In the second S+1.27- site, S+1.27- is bonded in a 1-coordinate geometry to two K1+, two Nb5+, and one S+1.27- atom. The S–S bond length is 2.08 Å. In the third S+1.27- site, S+1.27- is bonded in a 5-coordinate geometry to three K1+, one Nb5+, and one S+1.27- atom. The S–S bond length is 2.09 Å. In the fourth S+1.27- site, S+1.27- is bonded in a 5-coordinate geometry to three K1+, one Nb5+, and one S+1.27- atom. In the fifth S+1.27- site, S+1.27- is bonded in a 5-coordinate geometry to three K1+, one Nb5+, and one S+1.27- atom. In the sixth S+1.27- site, S+1.27- is bonded in a distorted rectangular see-saw-like geometry to three K1+ and one Nb5+ atom. In the seventh S+1.27- site, S+1.27- is bonded in a 5-coordinate geometry to three K1+ and two Nb5+ atoms. In the eighth S+1.27- site, S+1.27- is bonded in a 5-coordinate geometry to two K1+, two Nb5+, and one S+1.27- atom. The S–S bond length is 2.08 Å. In the ninth S+1.27- site, S+1.27- is bonded in a distorted rectangular see-saw-like geometry to three K1+ and one Nb5+ atom. In the tenth S+1.27- site, S+1.27- is bonded in a 4-coordinate geometry to two K1+, one Nb5+, and one S+1.27- atom. In the eleventh S+1.27- site, S+1.27- is bonded in a distorted trigonal bipyramidal geometry to three K1+, one Nb5+, and one S+1.27- atom.