Materials Data on Na3Eu2(SiTe3)2 by Materials Project

Abstract

Na3Eu2(SiTe3)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 Te+1.50- atoms to form NaTe6 octahedra that share corners with four equivalent EuTe6 octahedra, corners with two equivalent SiSiTe3 tetrahedra, edges with four equivalent EuTe6 octahedra, edges with six NaTe6 octahedra, and edges with two equivalent SiSiTe3 tetrahedra. The corner-sharing octahedral tilt angles are 5°. There are a spread of Na–Te bond distances ranging from 3.27–3.40 Å. In the second Na1+ site, Na1+ is bonded to six Te+1.50- atoms to form NaTe6 octahedra that share corners with four equivalent EuTe6 octahedra, corners with two equivalent SiSiTe3 tetrahedra, edges with four equivalent EuTe6 octahedra, edges with six equivalent NaTe6 octahedra, and edges with two equivalent SiSiTe3 tetrahedra. The corner-sharing octahedral tilt angles are 5°. There are four shorter (3.28 Å) and two longer (3.42 Å) Na–Te bond lengths. Eu3+ is bonded to six Te+1.50- atoms to form EuTe6 octahedra that share corners with six NaTe6 octahedra, corners with six equivalent SiSiTe3 tetrahedra, edges with three equivalent EuTe6 octahedra, and edges with six NaTe6 octahedra. The corner-sharing octahedral tilt angles are 5°. There are two shorter (3.30 Å) and four longer (3.31 Å) Eu–Te bond lengths. Si is bonded to one Si and three Te+1.50- atoms to form SiSiTe3 tetrahedra that share corners with three NaTe6 octahedra, corners with three TeNa3Eu2Si octahedra, corners with six equivalent EuTe6 octahedra, and edges with three NaTe6 octahedra. The corner-sharing octahedra tilt angles range from 20–77°. The Si–Si bond length is 2.38 Å. There are one shorter (2.59 Å) and two longer (2.60 Å) Si–Te bond lengths. There are two inequivalent Te+1.50- sites. In the first Te+1.50- site, Te+1.50- is bonded to three Na1+, two equivalent Eu3+, and one Si atom to form TeNa3Eu2Si octahedra that share corners with seven TeNa3Eu2Si octahedra, a cornercorner with one SiSiTe3 tetrahedra, and edges with ten TeNa3Eu2Si octahedra. The corner-sharing octahedra tilt angles range from 0–91°. In the second Te+1.50- site, Te+1.50- is bonded to three Na1+, two equivalent Eu3+, and one Si atom to form TeNa3Eu2Si octahedra that share corners with seven TeNa3Eu2Si octahedra, a cornercorner with one SiSiTe3 tetrahedra, and edges with ten TeNa3Eu2Si octahedra. The corner-sharing octahedra tilt angles range from 0–91°.