Materials Data on Er7(CuTe4)3 by Materials Project

Er7Cu3Te12 is Corundum-derived structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are five inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded to six Te2- atoms to form ErTe6 octahedra that share a cornercorner with one ErTe6 octahedra, corners with three CuTe4 tetrahedra, and edges with seven ErTe6 octahedra. The corner-sharing octahedral tilt angles are 3°. There are a spread of Er–Te bond distances ranging from 3.02–3.10 Å. In the second Er3+ site, Er3+ is bonded to six Te2- atoms to form ErTe6 octahedra that share a cornercorner with one ErTe6 octahedra, corners with three CuTe4 tetrahedra, edges with seven ErTe6 octahedra, and edges with three CuTe4 tetrahedra. The corner-sharing octahedral tilt angles are 1°. There are a spread of Er–Te bond distances ranging from 3.04–3.12 Å. In the third Er3+ site, Er3+ is bonded to six Te2- atoms to form a mixture of corner and edge-sharing ErTe6 octahedra. The corner-sharing octahedra tilt angles range from 1–3°. There are a spread of Er–Te bond distances ranging from 2.99–3.10 Å. In the fourth Er3+ site, Er3+ is bonded to six Te2- atoms to form ErTe6 octahedra that share a cornercorner with one ErTe6 octahedra, corners with three CuTe4 tetrahedra, edges with seven ErTe6 octahedra, and edges with three CuTe4 tetrahedra. The corner-sharing octahedral tilt angles are 1°. There are a spread of Er–Te bond distances ranging from 3.05–3.12 Å. In the fifth Er3+ site, Er3+ is bonded to six Te2- atoms to form ErTe6 octahedra that share a cornercorner with one ErTe6 octahedra, corners with three CuTe4 tetrahedra, and edges with seven ErTe6 octahedra. The corner-sharing octahedral tilt angles are 3°. There are a spread of Er–Te bond distances ranging from 3.02–3.10 Å. There are two inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded to four Te2- atoms to form CuTe4 tetrahedra that share corners with six ErTe6 octahedra, corners with six CuTe4 tetrahedra, and edges with three ErTe6 octahedra. The corner-sharing octahedra tilt angles range from 19–56°. There are a spread of Cu–Te bond distances ranging from 2.59–2.63 Å. In the second Cu1+ site, Cu1+ is bonded to four Te2- atoms to form CuTe4 tetrahedra that share corners with six ErTe6 octahedra, corners with six equivalent CuTe4 tetrahedra, and edges with three ErTe6 octahedra. The corner-sharing octahedra tilt angles range from 19–55°. There are a spread of Cu–Te bond distances ranging from 2.58–2.63 Å. There are eight inequivalent Te2- sites. In the first Te2- site, Te2- is bonded to three Er3+ and three Cu1+ atoms to form distorted edge-sharing TeEr3Cu3 octahedra. In the second Te2- site, Te2- is bonded in a rectangular see-saw-like geometry to four Er3+ atoms. In the third Te2- site, Te2- is bonded in a rectangular see-saw-like geometry to four Er3+ atoms. In the fourth Te2- site, Te2- is bonded to three Er3+ and three Cu1+ atoms to form distorted edge-sharing TeEr3Cu3 octahedra. In the fifth Te2- site, Te2- is bonded in a distorted rectangular see-saw-like geometry to three Er3+ and one Cu1+ atom. In the sixth Te2- site, Te2- is bonded in a rectangular see-saw-like geometry to four Er3+ atoms. In the seventh Te2- site, Te2- is bonded in a rectangular see-saw-like geometry to four Er3+ atoms. In the eighth Te2- site, Te2- is bonded in a rectangular see-saw-like geometry to three Er3+ and one Cu1+ atom.