DOE OSTI2020
EuLu2Se4 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Lu3+ sites. In the first Lu3+ site, Lu3+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing LuSe6 octahedra. The corner-sharing octahedra tilt angles range from 47–62°. There are a spread of Lu–Se bond distances ranging from 2.78–2.84 Å. In the second Lu3+ site, Lu3+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing LuSe6 octahedra. The corner-sharing octahedra tilt angles range from 47–62°. There are a spread of Lu–Se bond distances ranging from 2.76–2.84 Å. Eu2+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Eu–Se bond distances ranging from 3.15–3.40 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 5-coordinate geometry to three Lu3+ and two equivalent Eu2+ atoms. In the second Se2- site, Se2- is bonded in a 5-coordinate geometry to three Lu3+ and two equivalent Eu2+ atoms. In the third Se2- site, Se2- is bonded to three equivalent Lu3+ and two equivalent Eu2+ atoms to form distorted edge-sharing SeEu2Lu3 square pyramids. In the fourth Se2- site, Se2- is bonded in a 5-coordinate geometry to three equivalent Lu3+ and two equivalent Eu2+ atoms.