Materials Data on As9Pb7S20 by Materials Project
Pb7As9S20 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are seven inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of Pb–S bond distances ranging from 2.78–3.51 Å. In the second Pb2+ site, Pb2+ is bonded to six S2- atoms to form distorted edge-sharing PbS6 pentagonal pyramids. There are a spread of Pb–S bond distances ranging from 2.86–3.15 Å. In the third Pb2+ site, Pb2+ is bonded to six S2- atoms to form distorted edge-sharing PbS6 pentagonal pyramids. There are a spread of Pb–S bond distances ranging from 2.87–3.23 Å. In the fourth Pb2+ site, Pb2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Pb–S bond distances ranging from 2.85–3.51 Å. In the fifth Pb2+ site, Pb2+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of Pb–S bond distances ranging from 2.80–3.55 Å. In the sixth Pb2+ site, Pb2+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of Pb–S bond distances ranging from 2.91–3.21 Å. In the seventh Pb2+ site, Pb2+ is bonded in a 6-coordinate geometry to nine S2- atoms. There are a spread of Pb–S bond distances ranging from 2.92–3.76 Å. There are nine inequivalent As+2.89+ sites. In the first As+2.89+ site, As+2.89+ is bonded in a distorted trigonal non-coplanar geometry to three S2- atoms. There are a spread of As–S bond distances ranging from 2.27–2.32 Å. In the second As+2.89+ site, As+2.89+ is bonded in a 4-coordinate geometry to three S2- atoms. There are a spread of As–S bond distances ranging from 2.23–2.58 Å. In the third As+2.89+ site, As+2.89+ is bonded in a 4-coordinate geometry to four S2- atoms. There are a spread of As–S bond distances ranging from 2.27–2.96 Å. In the fourth As+2.89+ site, As+2.89+ is bonded in a 3-coordinate geometry to three S2- atoms. There are a spread of As–S bond distances ranging from 2.25–2.79 Å. In the fifth As+2.89+ site, As+2.89+ is bonded in a distorted rectangular see-saw-like geometry to four S2- atoms. There are a spread of As–S bond distances ranging from 2.27–3.00 Å. In the sixth As+2.89+ site, As+2.89+ is bonded in a distorted rectangular see-saw-like geometry to four S2- atoms. There are a spread of As–S bond distances ranging from 2.26–2.64 Å. In the seventh As+2.89+ site, As+2.89+ is bonded in a distorted trigonal non-coplanar geometry to three S2- atoms. There are two shorter (2.29 Å) and one longer (2.30 Å) As–S bond lengths. In the eighth As+2.89+ site, As+2.89+ is bonded in a distorted trigonal non-coplanar geometry to three S2- atoms. There are a spread of As–S bond distances ranging from 2.20–2.38 Å. In the ninth As+2.89+ site, As+2.89+ is bonded in a 3-coordinate geometry to three S2- atoms. There are a spread of As–S bond distances ranging from 2.26–2.36 Å. There are twenty inequivalent S2- sites. In the first S2- site, S2- is bonded in a 3-coordinate geometry to one Pb2+ and two As+2.89+ atoms. In the second S2- site, S2- is bonded in a 1-coordinate geometry to three Pb2+ and one As+2.89+ atom. In the third S2- site, S2- is bonded in a distorted water-like geometry to two Pb2+ and two As+2.89+ atoms. In the fourth S2- site, S2- is bonded in a 1-coordinate geometry to three Pb2+ and one As+2.89+ atom. In the fifth S2- site, S2- is bonded in a distorted water-like geometry to one Pb2+ and two As+2.89+ atoms. In the sixth S2- site, S2- is bonded in a 3-coordinate geometry to three Pb2+ and one As+2.89+ atom. In the seventh S2- site, S2- is bonded in a 1-coordinate geometry to four Pb2+ and one As+2.89+ atom. In the eighth S2- site, S2- is bonded in a 2-coordinate geometry to one Pb2+ and two As+2.89+ atoms. In the ninth S2- site, S2- is bonded in a 4-coordinate geometry to one Pb2+ and three As+2.89+ atoms. In the tenth S2- site, S2- is bonded in a 2-coordinate geometry to two Pb2+ and two As+2.89+ atoms. In the eleventh S2- site, S2- is bonded in a 1-coordinate geometry to three Pb2+ and one As+2.89+ atom. In the twelfth S2- site, S2- is bonded in a distorted single-bond geometry to three Pb2+ and one As+2.89+ atom. In the thirteenth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to two Pb2+ and two As+2.89+ atoms. In the fourteenth S2- site, S2- is bonded in a 1-coordinate geometry to two Pb2+ and two As+2.89+ atoms. In the fifteenth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to three Pb2+ and one As+2.89+ atom. In the sixteenth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to two Pb2+ and two As+2.89+ atoms. In the seventeenth S2- site, S2- is bonded in a 1-coordinate geometry to two Pb2+ and one As+2.89+ atom. In the eighteenth S2- site, S2- is bonded in a 1-coordinate geometry to four Pb2+ and one As+2.89+ atom. In the nineteenth S2- site, S2- is bonded in a 1-coordinate geometry to three Pb2+ and one As+2.89+ atom. In the twentieth S2- site, S2- is bonded in a distorted single-bond geometry to two Pb2+ and one As+2.89+ atom.