Materials Data on NaHfCuSe3 by Materials Project
NaHfCuSe3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Na1+ is bonded in a 7-coordinate geometry to seven Se2- atoms. There are a spread of Na–Se bond distances ranging from 3.02–3.47 Å. Hf4+ is bonded to six Se2- atoms to form HfSe6 octahedra that share a cornercorner with one CuSe4 tetrahedra, edges with four equivalent HfSe6 octahedra, and edges with two equivalent CuSe4 tetrahedra. There are a spread of Hf–Se bond distances ranging from 2.61–2.79 Å. Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share a cornercorner with one HfSe6 octahedra, corners with two equivalent CuSe4 tetrahedra, edges with two equivalent HfSe6 octahedra, and edges with two equivalent CuSe4 tetrahedra. The corner-sharing octahedral tilt angles are 68°. There are a spread of Cu–Se bond distances ranging from 2.44–2.55 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to two equivalent Na1+ and three equivalent Hf4+ atoms to form distorted edge-sharing SeNa2Hf3 trigonal bipyramids. In the second Se2- site, Se2- is bonded in a 6-coordinate geometry to two equivalent Na1+, one Hf4+, and three equivalent Cu1+ atoms. In the third Se2- site, Se2- is bonded in a 6-coordinate geometry to three equivalent Na1+, two equivalent Hf4+, and one Cu1+ atom.