Materials Data on Na3Eu2(GeSe3)2 by Materials Project
Na3Eu2(GeSe3)2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six Se2- atoms to form NaSe6 octahedra that share corners with four equivalent EuSe6 octahedra, edges with four equivalent EuSe6 octahedra, and edges with six NaSe6 octahedra. The corner-sharing octahedral tilt angles are 2°. There are a spread of Na–Se bond distances ranging from 3.08–3.17 Å. In the second Na1+ site, Na1+ is bonded to six Se2- atoms to form NaSe6 octahedra that share corners with four equivalent EuSe6 octahedra, edges with four equivalent EuSe6 octahedra, and edges with six equivalent NaSe6 octahedra. The corner-sharing octahedral tilt angles are 1°. There are four shorter (3.12 Å) and two longer (3.13 Å) Na–Se bond lengths. Eu+2.50+ is bonded to six Se2- atoms to form EuSe6 octahedra that share corners with six NaSe6 octahedra, edges with three equivalent EuSe6 octahedra, and edges with six NaSe6 octahedra. The corner-sharing octahedra tilt angles range from 1–2°. There are two shorter (3.12 Å) and four longer (3.13 Å) Eu–Se bond lengths. Ge2+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are one shorter (2.52 Å) and two longer (2.53 Å) Ge–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to three Na1+, two equivalent Eu+2.50+, and one Ge2+ atom to form a mixture of edge and corner-sharing SeNa3Eu2Ge octahedra. The corner-sharing octahedra tilt angles range from 0–87°. In the second Se2- site, Se2- is bonded to three Na1+, two equivalent Eu+2.50+, and one Ge2+ atom to form a mixture of edge and corner-sharing SeNa3Eu2Ge octahedra. The corner-sharing octahedra tilt angles range from 0–87°.