Materials Data on Na2Cu2TeO6 by Materials Project
Na2Cu2TeO6 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with two equivalent TeO6 octahedra, edges with two equivalent TeO6 octahedra, and edges with three equivalent NaO6 octahedra. The corner-sharing octahedral tilt angles are 15°. There are a spread of Na–O bond distances ranging from 2.32–2.53 Å. Cu2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Cu–O bond distances ranging from 1.99–2.65 Å. Te6+ is bonded to six O2- atoms to form TeO6 octahedra that share corners with four equivalent NaO6 octahedra and edges with four equivalent NaO6 octahedra. The corner-sharing octahedral tilt angles are 15°. There is four shorter (1.95 Å) and two longer (2.03 Å) Te–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Na1+, two equivalent Cu2+, and one Te6+ atom to form a mixture of distorted edge and corner-sharing ONa2Cu2Te trigonal bipyramids. In the second O2- site, O2- is bonded to two equivalent Na1+, two equivalent Cu2+, and one Te6+ atom to form a mixture of distorted edge and corner-sharing ONa2Cu2Te square pyramids.