Materials Data on Ca3Cu3(AsO4)4 by Materials Project
Ca3Cu3(AsO4)4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 5-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.33–2.83 Å. In the second Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six AsO4 tetrahedra and edges with two equivalent CuO5 trigonal bipyramids. There are a spread of Ca–O bond distances ranging from 2.29–2.44 Å. There are two inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded to five O2- atoms to form CuO5 trigonal bipyramids that share corners with five AsO4 tetrahedra and an edgeedge with one CaO6 octahedra. There are a spread of Cu–O bond distances ranging from 1.91–2.35 Å. In the second Cu2+ site, Cu2+ is bonded in a square co-planar geometry to four O2- atoms. All Cu–O bond lengths are 1.96 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 CaO6 octahedra and corners with three equivalent CuO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 47–61°. There are a spread of As–O bond distances ranging from 1.69–1.75 Å. In the second As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share a cornercorner with one CaO6 octahedra and corners with two equivalent CuO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 54°. There are a spread of As–O bond distances ranging from 1.69–1.78 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, two Cu2+, and one As5+ atom. In the second O2- site, O2- is bonded to two Ca2+, one Cu2+, and one As5+ atom to form distorted corner-sharing OCa2CuAs tetrahedra. In the third O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Ca2+, one Cu2+, and one As5+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Cu2+, and one As5+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ca2+ and one As5+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Cu2+, and one As5+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Cu2+, and one As5+ atom. In the eighth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ca2+ and one As5+ atom.