Materials Data on Sr3GaAs3 by Materials Project

Abstract

Sr3GaAs3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are four inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to six As3- atoms to form distorted SrAs6 octahedra that share corners with five equivalent SrAs6 octahedra, corners with four equivalent GaAs4 tetrahedra, edges with eight SrAs6 octahedra, and a faceface with one GaAs4 tetrahedra. The corner-sharing octahedra tilt angles range from 15–23°. There are a spread of Sr–As bond distances ranging from 3.19–3.50 Å. In the second Sr2+ site, Sr2+ is bonded to six As3- atoms to form distorted SrAs6 octahedra that share corners with five equivalent SrAs6 octahedra, corners with four equivalent GaAs4 tetrahedra, edges with eight SrAs6 octahedra, and a faceface with one GaAs4 tetrahedra. The corner-sharing octahedra tilt angles range from 12–25°. There are a spread of Sr–As bond distances ranging from 3.17–3.52 Å. In the third Sr2+ site, Sr2+ is bonded in a 6-coordinate geometry to six As3- atoms. There are a spread of Sr–As bond distances ranging from 3.16–3.46 Å. In the fourth Sr2+ site, Sr2+ is bonded in a 6-coordinate geometry to six As3- atoms. There are a spread of Sr–As bond distances ranging from 3.18–3.43 Å. Ga3+ is bonded to four As3- atoms to form GaAs4 tetrahedra that share corners with eight SrAs6 octahedra, an edgeedge with one GaAs4 tetrahedra, and faces with two SrAs6 octahedra. The corner-sharing octahedra tilt angles range from 37–58°. There are a spread of Ga–As bond distances ranging from 2.52–2.57 Å. There are four inequivalent As3- sites. In the first As3- site, As3- is bonded in a 8-coordinate geometry to six Sr2+ and two equivalent Ga3+ atoms. In the second As3- site, As3- is bonded in a 8-coordinate geometry to six Sr2+ and two equivalent Ga3+ atoms. In the third As3- site, As3- is bonded to six Sr2+ and one Ga3+ atom to form a mixture of distorted edge and corner-sharing AsSr6Ga pentagonal bipyramids. In the fourth As3- site, As3- is bonded in a 7-coordinate geometry to six Sr2+ and one Ga3+ atom.