DOE OSTI2020
SAs crystallizes in the triclinic P1 space group. The structure is one-dimensional and consists of two arsenic compounds molecules; one As4S3 cluster; one SAs cluster; one SSAs cluster; one As3S4 ribbon oriented in the (1, 0, 0) direction; and two SAs ribbons oriented in the (1, 0, 0) direction. In the As4S3 cluster, there are four inequivalent As2+ sites. In the first As2+ site, As2+ is bonded in a water-like geometry to two S2- atoms. There are one shorter (2.26 Å) and one longer (2.27 Å) As–S bond lengths. In the second As2+ site, As2+ is bonded in a single-bond geometry to one S2- atom. The As–S bond length is 2.28 Å. In the third As2+ site, As2+ is bonded in a water-like geometry to two S2- atoms. There are one shorter (2.28 Å) and one longer (2.29 Å) As–S bond lengths. In the fourth As2+ site, As2+ is bonded in a single-bond geometry to one S2- atom. The As–S bond length is 2.26 Å. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a 3-coordinate geometry to two As2+ atoms. In the second S2- site, S2- is bonded in a bent 120 degrees geometry to two As2+ atoms. In the third S2- site, S2- is bonded in a bent 120 degrees geometry to two As2+ atoms. In the SAs cluster, there are two inequivalent As2+ sites. In the first As2+ site, As2+ is bonded in a single-bond geometry to one S2- atom. The As–S bond length is 2.31 Å. In the second As2+ site, As2+ is bonded in a single-bond geometry to one S2- atom. The As–S bond length is 2.32 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted water-like geometry to one As2+ and one S2- atom. The S–S bond length is 2.09 Å. In the second S2- site, S2- is bonded in a distorted water-like geometry to one As2+ and one S2- atom. In the SSAs cluster, there are two inequivalent As2+ sites. In the first As2+ site, As2+ is bonded in a water-like geometry to two S2- atoms. There are one shorter (2.30 Å) and one longer (2.35 Å) As–S bond lengths. In the second As2+ site, As2+ is bonded in a water-like geometry to two S2- atoms. There are one shorter (2.29 Å) and one longer (2.35 Å) As–S bond lengths. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a water-like geometry to two As2+ atoms. In the second S2- site, S2- is bonded in a water-like geometry to two S2- atoms. There are one shorter (2.05 Å) and one longer (2.06 Å) S–S bond lengths. In the third S2- site, S2- is bonded in a distorted water-like geometry to one As2+ and one S2- atom. In the fourth S2- site, S2- is bonded in a distorted water-like geometry to one As2+ and one S2- atom. In the As3S4 ribbon, there are three inequivalent As2+ sites. In the first As2+ site, As2+ is bonded in a trigonal non-coplanar geometry to three S2- atoms. There are a spread of As–S bond distances ranging from 2.25–2.36 Å. In the second As2+ site, As2+ is bonded in a water-like geometry to two S2- atoms. There are one shorter (2.26 Å) and one longer (2.33 Å) As–S bond lengths. In the third As2+ site, As2+ is bonded in a single-bond geometry to one S2- atom. The As–S bond length is 2.28 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted water-like geometry to one As2+ and one S2- atom. The S–S bond length is 2.04 Å. In the second S2- site, S2- is bonded in a distorted water-like geometry to one As2+ and one S2- atom. In the third S2- site, S2- is bonded in a water-like geometry to two As2+ atoms. In the fourth S2- site, S2- is bonded in a water-like geometry to two As2+ atoms. In one of the SAs ribbons, there are five inequivalent As2+ sites. In the first As2+ site, As2+ is bonded in a water-like geometry to two S2- atoms. There are one shorter (2.26 Å) and one longer (2.30 Å) As–S bond lengths. In the second As2+ site, As2+ is bonded in a 3-coordinate geometry to three S2- atoms. There are a spread of As–S bond distances ranging from 2.11–2.86 Å. In the third As2+ site, As2+ is bonded in a distorted T-shaped geometry to three S2- atoms. There are a spread of As–S bond distances ranging from 2.28–2.32 Å. In the fourth As2+ site, As2+ is bonded in a single-bond geometry to one S2- atom. The As–S bond length is 2.31 Å. In the fifth As2+ site, As2+ is bonded in a single-bond geometry to one S2- atom. The As–S bond length is 2.28 Å. There are five inequivalent S2- sites. In the first S2- site, S2- is bonded in a single-bond geometry to one As2+ atom. In the second S2- site, S2- is bonded in a water-like geometry to two As2+ atoms. In the third S2- site, S2- is bonded in a water-like geometry to two As2+ atoms. In the fourth S2- site, S2- is bonded in a water-like geometry to two As2+ atoms. In the fifth S2- site, S2- is bonded in a 3-coordinate geometry to three As2+ atoms. In one of the SAs ribbons, there are six inequivalent As2+ sites. In the first As2+ site, As2+ is bonded in a single-bond geometry to one S2- atom. The As–S bond length is 2.31 Å. In the second As2+ site, As2+ is bonded in a water-like geometry to two S2- atoms. There are one shorter (2.27 Å) and one longer (2.34 Å) As–S bond lengths. In the third As2+ site, As2+ is bonded in a distorted trigonal non-coplanar geometry to three S2- atoms. There are a spread of As–S bond distances ranging from 2.28–2.33 Å. In the fourth As2+ site, As2+ is bonded in a single-bond geometry to one S2- atom. The As–S bond length is 2.27 Å. In the fifth As2+ site, As2+ is bonded in a water-like geometry to two S2- atoms. There are one shorter (2.25 Å) and one longer (2.27 Å) As–S bond lengths. In the sixth As2+ site, As2+ is bonded in a trigonal non-coplanar geometry to three S2- atoms. There are a spread of As–S bond distances ranging from 2.28–2.30 Å. There are six inequivalent S2- sites. In the first S2- site, S2- is bonded in a bent 120 degrees geometry to two As2+ atoms. In the second S2- site, S2- is bonded in a water-like geometry to two As2+ atoms. In the third S2- site, S2- is bonded in a water-like geometry to two As2+ atoms. In the fourth S2- site, S2- is bonded in a bent 120 degrees geometry to two As2+ atoms. In the fifth S2- site, S2- is bonded in a water-like geometry to two As2+ atoms. In the sixth S2- site, S2- is bonded in a water-like geometry to two As2+ atoms.