Materials Data on Sr3(SnAs2)2 by Materials Project
Sr3Sn2As4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are three inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to six As3- atoms to form a mixture of corner and edge-sharing SrAs6 octahedra. The corner-sharing octahedra tilt angles range from 5–9°. There are a spread of Sr–As bond distances ranging from 3.21–3.32 Å. In the second Sr2+ site, Sr2+ is bonded to six As3- atoms to form a mixture of corner and edge-sharing SrAs6 octahedra. The corner-sharing octahedra tilt angles range from 3–9°. There are a spread of Sr–As bond distances ranging from 3.22–3.36 Å. In the third Sr2+ site, Sr2+ is bonded to six As3- atoms to form a mixture of corner and edge-sharing SrAs6 octahedra. The corner-sharing octahedra tilt angles range from 3–8°. There are a spread of Sr–As bond distances ranging from 3.16–3.36 Å. There are two inequivalent Sn3+ sites. In the first Sn3+ site, Sn3+ is bonded in a trigonal non-coplanar geometry to three As3- atoms. There are a spread of Sn–As bond distances ranging from 2.60–2.71 Å. In the second Sn3+ site, Sn3+ is bonded in a trigonal non-coplanar geometry to three As3- atoms. There are a spread of Sn–As bond distances ranging from 2.66–2.69 Å. There are four inequivalent As3- sites. In the first As3- site, As3- is bonded to four Sr2+ and two equivalent Sn3+ atoms to form a mixture of corner and edge-sharing AsSr4Sn2 octahedra. The corner-sharing octahedra tilt angles range from 6–88°. In the second As3- site, As3- is bonded to five Sr2+ and one Sn3+ atom to form a mixture of corner and edge-sharing AsSr5Sn octahedra. The corner-sharing octahedra tilt angles range from 3–82°. In the third As3- site, As3- is bonded to four Sr2+ and two Sn3+ atoms to form a mixture of corner and edge-sharing AsSr4Sn2 octahedra. The corner-sharing octahedra tilt angles range from 5–89°. In the fourth As3- site, As3- is bonded to five Sr2+ and one Sn3+ atom to form a mixture of corner and edge-sharing AsSr5Sn octahedra. The corner-sharing octahedra tilt angles range from 3–88°.