Materials Data on Er4C7 by Materials Project
Er4C7 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded in a 9-coordinate geometry to nine C+1.71- atoms. There are a spread of Er–C bond distances ranging from 2.42–2.83 Å. In the second Er3+ site, Er3+ is bonded to seven C+1.71- atoms to form distorted ErC7 octahedra that share corners with two equivalent ErC7 octahedra, a cornercorner with one CEr4C trigonal bipyramid, and edges with five equivalent ErC7 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Er–C bond distances ranging from 2.47–2.98 Å. There are four inequivalent C+1.71- sites. In the first C+1.71- site, C+1.71- is bonded in a 5-coordinate geometry to five Er3+ and one C+1.71- atom. The C–C bond length is 1.33 Å. In the second C+1.71- site, C+1.71- is bonded to four Er3+ and one C+1.71- atom to form distorted CEr4C trigonal bipyramids that share a cornercorner with one ErC7 octahedra, a cornercorner with one CEr6 octahedra, corners with six equivalent CEr4C trigonal bipyramids, and edges with two equivalent CEr6 octahedra. The corner-sharing octahedra tilt angles range from 32–61°. The C–C bond length is 1.32 Å. In the third C+1.71- site, C+1.71- is bonded in a 6-coordinate geometry to four Er3+ and two C+1.71- atoms. In the fourth C+1.71- site, C+1.71- is bonded to six Er3+ atoms to form CEr6 octahedra that share corners with two equivalent CEr4C trigonal bipyramids, edges with two equivalent CEr6 octahedra, and edges with four equivalent CEr4C trigonal bipyramids.