Materials Data on Sr14(SnAs4)3 by Materials Project
Sr14(SnAs4)3 crystallizes in the trigonal R3 space group. The structure is three-dimensional. there are six inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to six As3- atoms to form a mixture of distorted corner, edge, and face-sharing SrAs6 octahedra. The corner-sharing octahedra tilt angles range from 15–49°. There are a spread of Sr–As bond distances ranging from 3.14–3.59 Å. In the second Sr2+ site, Sr2+ is bonded to six As3- atoms to form a mixture of distorted corner, edge, and face-sharing SrAs6 octahedra. The corner-sharing octahedra tilt angles range from 13–66°. There are a spread of Sr–As bond distances ranging from 3.12–3.61 Å. In the third Sr2+ site, Sr2+ is bonded to six As3- atoms to form a mixture of distorted corner, edge, and face-sharing SrAs6 octahedra. The corner-sharing octahedra tilt angles range from 13–48°. There are a spread of Sr–As bond distances ranging from 3.10–3.57 Å. In the fourth Sr2+ site, Sr2+ is bonded to six As3- atoms to form a mixture of distorted corner, edge, and face-sharing SrAs6 octahedra. The corner-sharing octahedra tilt angles range from 15–57°. There are a spread of Sr–As bond distances ranging from 3.19–3.50 Å. In the fifth Sr2+ site, Sr2+ is bonded to six As3- atoms to form a mixture of corner, edge, and face-sharing SrAs6 octahedra. The corner-sharing octahedra tilt angles range from 15–50°. There are three shorter (3.27 Å) and three longer (3.34 Å) Sr–As bond lengths. In the sixth Sr2+ site, Sr2+ is bonded to six As3- atoms to form a mixture of distorted corner, edge, and face-sharing SrAs6 octahedra. The corner-sharing octahedra tilt angles range from 23–48°. There are three shorter (3.15 Å) and three longer (3.51 Å) Sr–As bond lengths. There are three inequivalent Sn+2.67+ sites. In the first Sn+2.67+ site, Sn+2.67+ is bonded in a trigonal non-coplanar geometry to three equivalent As3- atoms. All Sn–As bond lengths are 2.69 Å. In the second Sn+2.67+ site, Sn+2.67+ is bonded in a trigonal planar geometry to three equivalent As3- atoms. All Sn–As bond lengths are 2.66 Å. In the third Sn+2.67+ site, Sn+2.67+ is bonded in a trigonal non-coplanar geometry to three equivalent As3- atoms. All Sn–As bond lengths are 2.81 Å. There are four inequivalent As3- sites. In the first As3- site, As3- is bonded in a 8-coordinate geometry to seven Sr2+ and one Sn+2.67+ atom. In the second As3- site, As3- is bonded to six Sr2+ and one Sn+2.67+ atom to form a mixture of distorted corner and edge-sharing AsSr6Sn pentagonal bipyramids. In the third As3- site, As3- is bonded in a 8-coordinate geometry to eight Sr2+ atoms. In the fourth As3- site, As3- is bonded in a 8-coordinate geometry to seven Sr2+ and one Sn+2.67+ atom.