Materials Data on Er5Co19P12 by Materials Project

Er5Co19P12 crystallizes in the trigonal P31m space group. The structure is three-dimensional. there are two inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded to six equivalent P3- atoms to form distorted ErP6 pentagonal pyramids that share corners with twelve CoP4 tetrahedra, edges with nine CoP4 tetrahedra, and faces with two equivalent ErP6 pentagonal pyramids. There are three shorter (2.80 Å) and three longer (2.81 Å) Er–P bond lengths. In the second Er3+ site, Er3+ is bonded to six P3- atoms to form distorted ErP6 pentagonal pyramids that share corners with four equivalent ErP6 pentagonal pyramids, corners with twelve CoP4 tetrahedra, edges with two equivalent ErP6 pentagonal pyramids, edges with eight CoP4 tetrahedra, and faces with two equivalent ErP6 pentagonal pyramids. There are a spread of Er–P bond distances ranging from 2.82–2.87 Å. There are five inequivalent Co+1.11+ sites. In the first Co+1.11+ site, Co+1.11+ is bonded to four P3- atoms to form CoP4 tetrahedra that share corners with four ErP6 pentagonal pyramids, corners with eight CoP4 tetrahedra, edges with three ErP6 pentagonal pyramids, and edges with four CoP4 tetrahedra. There are a spread of Co–P bond distances ranging from 2.25–2.33 Å. In the second Co+1.11+ site, Co+1.11+ is bonded in a 5-coordinate geometry to five P3- atoms. There are one shorter (2.21 Å) and four longer (2.58 Å) Co–P bond lengths. In the third Co+1.11+ site, Co+1.11+ is bonded to four P3- atoms to form CoP4 tetrahedra that share corners with two equivalent ErP6 pentagonal pyramids, corners with twelve CoP4 tetrahedra, edges with three ErP6 pentagonal pyramids, and edges with three CoP4 tetrahedra. There are a spread of Co–P bond distances ranging from 2.21–2.34 Å. In the fourth Co+1.11+ site, Co+1.11+ is bonded to four P3- atoms to form CoP4 tetrahedra that share corners with eight ErP6 pentagonal pyramids, corners with six CoP4 tetrahedra, edges with two equivalent ErP6 pentagonal pyramids, and edges with four equivalent CoP4 tetrahedra. There are two shorter (2.19 Å) and two longer (2.22 Å) Co–P bond lengths. In the fifth Co+1.11+ site, Co+1.11+ is bonded in a trigonal planar geometry to three equivalent P3- atoms. All Co–P bond lengths are 2.16 Å. There are three inequivalent P3- sites. In the first P3- site, P3- is bonded in a 9-coordinate geometry to four equivalent Er3+ and five Co+1.11+ atoms. In the second P3- site, P3- is bonded in a 9-coordinate geometry to two equivalent Er3+ and seven Co+1.11+ atoms. In the third P3- site, P3- is bonded in a 9-coordinate geometry to two equivalent Er3+ and seven Co+1.11+ atoms.