Materials Data on Ba2As2O7 by Materials Project
Ba2As2O7 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are four inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ba–O bond distances ranging from 2.69–3.24 Å. In the second Ba2+ site, Ba2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ba–O bond distances ranging from 2.74–2.99 Å. In the third Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ba–O bond distances ranging from 2.67–3.10 Å. In the fourth Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.76–3.07 Å. There are four inequivalent As5+ sites. In the first As5+ site, As5+ is bonded to four O2- atoms to form corner-sharing AsO4 tetrahedra. There are a spread of As–O bond distances ranging from 1.69–1.84 Å. In the second As5+ site, As5+ is bonded to four O2- atoms to form corner-sharing AsO4 tetrahedra. There are a spread of As–O bond distances ranging from 1.70–1.82 Å. In the third As5+ site, As5+ is bonded to four O2- atoms to form corner-sharing AsO4 tetrahedra. There are a spread of As–O bond distances ranging from 1.69–1.82 Å. In the fourth As5+ site, As5+ is bonded to four O2- atoms to form corner-sharing AsO4 tetrahedra. There are a spread of As–O bond distances ranging from 1.69–1.83 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Ba2+ and one As5+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to two Ba2+ and one As5+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to three Ba2+ and one As5+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ba2+ and two As5+ atoms. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to three Ba2+ and one As5+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ba2+ and one As5+ atom. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to three Ba2+ and one As5+ atom. In the eighth O2- site, O2- is bonded in a distorted single-bond geometry to three Ba2+ and one As5+ atom. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ba2+ and one As5+ atom. In the tenth O2- site, O2- is bonded in a distorted single-bond geometry to three Ba2+ and one As5+ atom. In the eleventh O2- site, O2- is bonded to three Ba2+ and one As5+ atom to form distorted edge-sharing OBa3As tetrahedra. In the twelfth O2- site, O2- is bonded in a 1-coordinate geometry to one Ba2+ and one As5+ atom. In the thirteenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ba2+ and two As5+ atoms. In the fourteenth O2- site, O2- is bonded in a distorted single-bond geometry to three Ba2+ and one As5+ atom.