Materials Data on K2CuPCO7 by Materials Project
K2CuCPO7 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. K1+ is bonded to seven O2- atoms to form distorted KO7 pentagonal bipyramids that share corners with two equivalent KO7 pentagonal bipyramids, corners with two equivalent PO4 tetrahedra, an edgeedge with one KO7 pentagonal bipyramid, an edgeedge with one PO4 tetrahedra, and a faceface with one KO7 pentagonal bipyramid. There are a spread of K–O bond distances ranging from 2.69–2.90 Å. Cu3+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are a spread of Cu–O bond distances ranging from 1.86–1.99 Å. C4+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.24 Å) and two longer (1.31 Å) C–O bond length. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four equivalent KO7 pentagonal bipyramids and edges with two equivalent KO7 pentagonal bipyramids. There are a spread of P–O bond distances ranging from 1.53–1.61 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent K1+ and one C4+ atom. In the second O2- site, O2- is bonded in a distorted L-shaped geometry to two equivalent K1+, one Cu3+, and one C4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent K1+, one Cu3+, and one C4+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent K1+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent K1+, one Cu3+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent K1+, one Cu3+, and one P5+ atom.