Materials Data on Er9Ge4S21 by Materials Project
Er9Ge4S21 crystallizes in the trigonal R3 space group. The structure is three-dimensional. there are six inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded in a 7-coordinate geometry to eight S2- atoms. There are a spread of Er–S bond distances ranging from 2.73–3.39 Å. In the second Er3+ site, Er3+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Er–S bond distances ranging from 2.64–3.08 Å. In the third Er3+ site, Er3+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Er–S bond distances ranging from 2.67–2.99 Å. In the fourth Er3+ site, Er3+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Er–S bond distances ranging from 2.64–3.08 Å. In the fifth Er3+ site, Er3+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Er–S bond distances ranging from 2.67–2.97 Å. In the sixth Er3+ site, Er3+ is bonded in a 7-coordinate geometry to eight S2- atoms. There are a spread of Er–S bond distances ranging from 2.73–3.39 Å. There are four inequivalent Ge+3.75+ sites. In the first Ge+3.75+ site, Ge+3.75+ is bonded in a tetrahedral geometry to four S2- atoms. There are a spread of Ge–S bond distances ranging from 2.22–2.25 Å. In the second Ge+3.75+ site, Ge+3.75+ is bonded in a tetrahedral geometry to four S2- atoms. There are one shorter (2.22 Å) and three longer (2.24 Å) Ge–S bond lengths. In the third Ge+3.75+ site, Ge+3.75+ is bonded in an octahedral geometry to six S2- atoms. There are three shorter (2.49 Å) and three longer (2.60 Å) Ge–S bond lengths. In the fourth Ge+3.75+ site, Ge+3.75+ is bonded in an octahedral geometry to six S2- atoms. There are three shorter (2.49 Å) and three longer (2.60 Å) Ge–S bond lengths. There are fourteen inequivalent S2- sites. In the first S2- site, S2- is bonded in a 3-coordinate geometry to four Er3+ atoms. In the second S2- site, S2- is bonded to three Er3+ and one Ge+3.75+ atom to form a mixture of edge and corner-sharing SEr3Ge trigonal pyramids. In the third S2- site, S2- is bonded in a 4-coordinate geometry to three Er3+ and one Ge+3.75+ atom. In the fourth S2- site, S2- is bonded in a 3-coordinate geometry to four Er3+ atoms. In the fifth S2- site, S2- is bonded to three Er3+ and one Ge+3.75+ atom to form a mixture of edge and corner-sharing SEr3Ge trigonal pyramids. In the sixth S2- site, S2- is bonded in a 4-coordinate geometry to three Er3+ and one Ge+3.75+ atom. In the seventh S2- site, S2- is bonded to three Er3+ and one Ge+3.75+ atom to form distorted corner-sharing SEr3Ge tetrahedra. In the eighth S2- site, S2- is bonded to three Er3+ and one Ge+3.75+ atom to form distorted corner-sharing SEr3Ge tetrahedra. In the ninth S2- site, S2- is bonded in a 4-coordinate geometry to three Er3+ and one Ge+3.75+ atom. In the tenth S2- site, S2- is bonded in a 4-coordinate geometry to three Er3+ and one Ge+3.75+ atom. In the eleventh S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to three Er3+ and one Ge+3.75+ atom. In the twelfth S2- site, S2- is bonded in a 4-coordinate geometry to three Er3+ and one Ge+3.75+ atom. In the thirteenth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to three Er3+ and one Ge+3.75+ atom. In the fourteenth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to three Er3+ and one Ge+3.75+ atom.