DOE OSTI2020
KCd6P7O24 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. K1+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.77–3.33 Å. There are three inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded to six O2- atoms to form CdO6 octahedra that share corners with six PO4 tetrahedra and edges with two CdO6 octahedra. There are a spread of Cd–O bond distances ranging from 2.24–2.48 Å. In the second Cd2+ site, Cd2+ is bonded to six O2- atoms to form distorted CdO6 octahedra that share corners with six PO4 tetrahedra and edges with three CdO6 octahedra. There are a spread of Cd–O bond distances ranging from 2.27–2.47 Å. In the third Cd2+ site, Cd2+ is bonded to six O2- atoms to form CdO6 octahedra that share corners with six PO4 tetrahedra and edges with three CdO6 octahedra. There are a spread of Cd–O bond distances ranging from 2.27–2.41 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with five CdO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 27–56°. There are a spread of P–O bond distances ranging from 1.51–1.62 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with five CdO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 44–60°. There are a spread of P–O bond distances ranging from 1.52–1.67 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four equivalent CdO6 octahedra and corners with two equivalent PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–53°. There is two shorter (1.52 Å) and two longer (1.59 Å) P–O bond length. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with six CdO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 43–61°. There are a spread of P–O bond distances ranging from 1.53–1.61 Å. There are thirteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Cd2+ and one P5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two Cd2+ and one P5+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to two Cd2+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two Cd2+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to one K1+, two equivalent Cd2+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to one K1+, two equivalent Cd2+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two P5+ atoms. In the ninth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+, one Cd2+, and one P5+ atom. In the tenth O2- site, O2- is bonded in a 1-coordinate geometry to one K1+, two Cd2+, and one P5+ atom. In the eleventh O2- site, O2- is bonded in a 1-coordinate geometry to two Cd2+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a 1-coordinate geometry to one K1+, one Cd2+, and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cd2+ and one P5+ atom.