Materials Data on Nb4AgS8 by Materials Project
Nb2AgS4(NbS2)2 crystallizes in the trigonal R3m space group. The structure is two-dimensional and consists of three Nb2AgS4 sheets oriented in the (0, 0, 1) direction and six NbS2 sheets oriented in the (0, 0, 1) direction. In each Nb2AgS4 sheet, there are two inequivalent Nb+3.75+ sites. In the first Nb+3.75+ site, Nb+3.75+ is bonded to six S2- atoms to form distorted edge-sharing NbS6 pentagonal pyramids. There are three shorter (2.48 Å) and three longer (2.52 Å) Nb–S bond lengths. In the second Nb+3.75+ site, Nb+3.75+ is bonded to six S2- atoms to form distorted edge-sharing NbS6 pentagonal pyramids. There are three shorter (2.48 Å) and three longer (2.51 Å) Nb–S bond lengths. Ag1+ is bonded in a 1-coordinate geometry to four S2- atoms. There are one shorter (2.46 Å) and three longer (2.75 Å) Ag–S bond lengths. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a rectangular see-saw-like geometry to three equivalent Nb+3.75+ and one Ag1+ atom. In the second S2- site, S2- is bonded in a 6-coordinate geometry to three equivalent Nb+3.75+ and three equivalent Ag1+ atoms. In the third S2- site, S2- is bonded in a 3-coordinate geometry to three equivalent Nb+3.75+ atoms. In the fourth S2- site, S2- is bonded in a 3-coordinate geometry to three equivalent Nb+3.75+ atoms. In each NbS2 sheet, Nb+3.75+ is bonded to six S2- atoms to form distorted edge-sharing NbS6 pentagonal pyramids. There are three shorter (2.50 Å) and three longer (2.51 Å) Nb–S bond lengths. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a 3-coordinate geometry to three equivalent Nb+3.75+ atoms. In the second S2- site, S2- is bonded in a 3-coordinate geometry to three equivalent Nb+3.75+ atoms.