Materials Data on BaCuAs2O7 by Materials Project
BaCuAs2O7 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.68–3.01 Å. Cu2+ is bonded in a distorted rectangular see-saw-like geometry to five O2- atoms. There are a spread of Cu–O bond distances ranging from 1.94–2.67 Å. There are two 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 1.69–1.78 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 1.68–1.81 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ba2+, one Cu2+, and one As5+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ba2+ and one As5+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Ba2+, one Cu2+, and one As5+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Ba2+, one Cu2+, and one As5+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ba2+, one Cu2+, and one As5+ atom. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Ba2+, one Cu2+, and one As5+ atom. In the seventh O2- site, O2- is bonded in a bent 120 degrees geometry to two As5+ atoms.