Materials Data on Na4Eu(SiTe3)2 by Materials Project

Na4Eu(SiTe3)2 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six Te1- atoms to form NaTe6 octahedra that share corners with two equivalent NaTe6 octahedra, corners with two equivalent EuTe6 octahedra, corners with two equivalent SiSiTe3 tetrahedra, edges with two equivalent EuTe6 octahedra, edges with eight NaTe6 octahedra, and edges with two equivalent SiSiTe3 tetrahedra. The corner-sharing octahedral tilt angles are 6°. There are a spread of Na–Te bond distances ranging from 3.26–3.42 Å. In the second Na1+ site, Na1+ is bonded to six Te1- atoms to form NaTe6 octahedra that share corners with two equivalent NaTe6 octahedra, corners with two equivalent EuTe6 octahedra, corners with two equivalent SiSiTe3 tetrahedra, edges with two equivalent EuTe6 octahedra, edges with eight NaTe6 octahedra, and edges with two equivalent SiSiTe3 tetrahedra. The corner-sharing octahedral tilt angles are 6°. There are a spread of Na–Te bond distances ranging from 3.25–3.42 Å. In the third Na1+ site, Na1+ is bonded to six Te1- atoms to form NaTe6 octahedra that share corners with two equivalent NaTe6 octahedra, corners with two equivalent EuTe6 octahedra, corners with two equivalent SiSiTe3 tetrahedra, edges with two equivalent EuTe6 octahedra, edges with eight NaTe6 octahedra, and edges with two equivalent SiSiTe3 tetrahedra. The corner-sharing octahedral tilt angles are 6°. There are a spread of Na–Te bond distances ranging from 3.25–3.45 Å. In the fourth Na1+ site, Na1+ is bonded to six Te1- atoms to form NaTe6 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 6°. There are a spread of Na–Te bond distances ranging from 3.30–3.32 Å. Eu2+ is bonded to six Te1- atoms to form EuTe6 octahedra that share corners with six NaTe6 octahedra, corners with six equivalent SiSiTe3 tetrahedra, and edges with nine NaTe6 octahedra. The corner-sharing octahedral tilt angles are 6°. There are a spread of Eu–Te bond distances ranging from 3.30–3.32 Å. Si is bonded to one Si and three Te1- atoms to form SiSiTe3 tetrahedra that share corners with three equivalent EuTe6 octahedra, corners with three TeNa4EuSi octahedra, corners with six NaTe6 octahedra, and edges with three NaTe6 octahedra. The corner-sharing octahedra tilt angles range from 19–77°. The Si–Si bond length is 2.37 Å. There are two shorter (2.54 Å) and one longer (2.55 Å) Si–Te bond lengths. There are three inequivalent Te1- sites. In the first Te1- site, Te1- is bonded to four Na1+, one Eu2+, and one Si atom to form TeNa4EuSi octahedra that share corners with seven TeNa4EuSi octahedra, a cornercorner with one SiSiTe3 tetrahedra, and edges with ten TeNa4EuSi octahedra. The corner-sharing octahedra tilt angles range from 0–91°. In the second Te1- site, Te1- is bonded to four Na1+, one Eu2+, and one Si atom to form TeNa4EuSi octahedra that share corners with seven TeNa4EuSi octahedra, a cornercorner with one SiSiTe3 tetrahedra, and edges with ten TeNa4EuSi octahedra. The corner-sharing octahedra tilt angles range from 0–91°. In the third Te1- site, Te1- is bonded to four Na1+, one Eu2+, and one Si atom to form TeNa4EuSi octahedra that share corners with seven TeNa4EuSi octahedra, a cornercorner with one SiSiTe3 tetrahedra, and edges with ten TeNa4EuSi octahedra. The corner-sharing octahedra tilt angles range from 0–91°.