Materials Data on KCd4P3 by Materials Project
KCd4P3 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. K1+ is bonded to six equivalent P3- atoms to form KP6 octahedra that share corners with six equivalent CdP4 tetrahedra and edges with six equivalent KP6 octahedra. All K–P bond lengths are 3.38 Å. There are two inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded in a distorted trigonal planar geometry to three equivalent P3- atoms. All Cd–P bond lengths are 2.60 Å. In the second Cd2+ site, Cd2+ is bonded to four P3- atoms to form CdP4 tetrahedra that share corners with three equivalent KP6 octahedra, corners with nine equivalent CdP4 tetrahedra, and edges with three equivalent CdP4 tetrahedra. The corner-sharing octahedral tilt angles are 49°. There are one shorter (2.61 Å) and three longer (2.79 Å) Cd–P bond lengths. There are two inequivalent P3- sites. In the first P3- site, P3- is bonded in a 7-coordinate geometry to three equivalent K1+ and four Cd2+ atoms. In the second P3- site, P3- is bonded in a 8-coordinate geometry to six equivalent Cd2+ atoms.