Materials Data on Ag7(SI)2 by Materials Project
Ag7(SI)2 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are seven inequivalent Ag sites. In the first Ag site, Ag is bonded to three equivalent Ag and three equivalent I atoms to form distorted AgAg3I3 octahedra that share corners with three equivalent IAg4 trigonal pyramids and edges with six equivalent AgAg3I3 octahedra. There are a spread of Ag–Ag bond distances ranging from 2.88–3.06 Å. There are a spread of Ag–I bond distances ranging from 2.95–3.17 Å. In the second Ag site, Ag is bonded in a distorted linear geometry to one S and one I atom. The Ag–S bond length is 2.41 Å. The Ag–I bond length is 2.68 Å. In the third Ag site, Ag is bonded in a 4-coordinate geometry to one S and three equivalent I atoms. The Ag–S bond length is 2.53 Å. There are a spread of Ag–I bond distances ranging from 2.82–3.10 Å. In the fourth Ag site, Ag is bonded in a distorted single-bond geometry to three equivalent Ag and one I atom. The Ag–I bond length is 2.81 Å. In the fifth Ag site, Ag is bonded in a linear geometry to two S atoms. There are one shorter (2.42 Å) and one longer (2.47 Å) Ag–S bond lengths. In the sixth Ag site, Ag is bonded in a bent 150 degrees geometry to two equivalent S atoms. There are one shorter (2.43 Å) and one longer (2.44 Å) Ag–S bond lengths. In the seventh Ag site, Ag is bonded in a 3-coordinate geometry to three equivalent S atoms. There are a spread of Ag–S bond distances ranging from 2.51–2.67 Å. There are two inequivalent S sites. In the first S site, S is bonded in a distorted see-saw-like geometry to four Ag atoms. In the second S site, S is bonded in a distorted pentagonal planar geometry to five Ag atoms. There are two inequivalent I sites. In the first I site, I is bonded to four Ag atoms to form distorted IAg4 trigonal pyramids that share corners with three equivalent AgAg3I3 octahedra and corners with six equivalent IAg4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 58–63°. In the second I site, I is bonded in a rectangular see-saw-like geometry to four Ag atoms.