Materials Data on Sr2VAs2O9 by Materials Project
Sr2VAs2O9 crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.63–2.91 Å. In the second Sr2+ site, Sr2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.55–2.80 Å. V4+ is bonded to six O2- atoms to form VO6 octahedra that share corners with two equivalent VO6 octahedra and corners with four AsO4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. There are a spread of V–O bond distances ranging from 1.71–2.13 Å. There are two inequivalent As5+ sites. In the first As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two equivalent VO6 octahedra. The corner-sharing octahedra tilt angles range from 49–55°. There is two shorter (1.69 Å) and two longer (1.75 Å) As–O bond length. In the second As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two equivalent VO6 octahedra. The corner-sharing octahedra tilt angles range from 41–49°. There is two shorter (1.71 Å) and two longer (1.74 Å) As–O bond length. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to three Sr2+ and one As5+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to three Sr2+ and one As5+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two Sr2+, one V4+, and one As5+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two Sr2+, one V4+, and one As5+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Sr2+ and two equivalent V4+ atoms. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to two Sr2+ and one As5+ atom. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to two Sr2+ and one As5+ atom. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to one Sr2+, one V4+, and one As5+ atom. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to one Sr2+, one V4+, and one As5+ atom.