Materials Data on Na2GaCuF7 by Materials Project
Na2CuGaF7 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Na–F bond distances ranging from 2.32–2.88 Å. In the second Na1+ site, Na1+ is bonded in a distorted body-centered cubic geometry to eight F1- atoms. There are a spread of Na–F bond distances ranging from 2.49–2.81 Å. In the third Na1+ site, Na1+ is bonded to eight F1- atoms to form distorted NaF8 hexagonal bipyramids that share corners with two equivalent GaF6 octahedra, edges with two equivalent GaF6 octahedra, and edges with four CuF6 octahedra. The corner-sharing octahedral tilt angles are 49°. There are a spread of Na–F bond distances ranging from 2.18–2.84 Å. There are two inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded to six F1- atoms to form CuF6 octahedra that share corners with two equivalent CuF6 octahedra, corners with four GaF6 octahedra, and edges with two equivalent NaF8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 42–48°. There are a spread of Cu–F bond distances ranging from 1.96–2.21 Å. In the second Cu2+ site, Cu2+ is bonded to six F1- atoms to form CuF6 octahedra that share corners with two equivalent CuF6 octahedra, corners with four GaF6 octahedra, and edges with two equivalent NaF8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 39–48°. There are a spread of Cu–F bond distances ranging from 1.95–2.16 Å. There are two inequivalent Ga3+ sites. In the first Ga3+ site, Ga3+ is bonded to six F1- atoms to form GaF6 octahedra that share corners with two equivalent NaF8 hexagonal bipyramids and corners with four CuF6 octahedra. The corner-sharing octahedra tilt angles range from 39–48°. There is four shorter (1.92 Å) and two longer (1.95 Å) Ga–F bond length. In the second Ga3+ site, Ga3+ is bonded to six F1- atoms to form GaF6 octahedra that share corners with four CuF6 octahedra and edges with two equivalent NaF8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 42–48°. There is two shorter (1.89 Å) and four longer (1.95 Å) Ga–F bond length. There are seven inequivalent F1- sites. In the first F1- site, F1- is bonded in a 4-coordinate geometry to two Na1+, one Cu2+, and one Ga3+ atom. In the second F1- site, F1- is bonded in a 2-coordinate geometry to two Na1+ and two Cu2+ atoms. In the third F1- site, F1- is bonded to three Na1+ and one Ga3+ atom to form a mixture of distorted edge and corner-sharing FNa3Ga tetrahedra. In the fourth F1- site, F1- is bonded in a 2-coordinate geometry to two equivalent Na1+, one Cu2+, and one Ga3+ atom. In the fifth F1- site, F1- is bonded in a 2-coordinate geometry to two Na1+, one Cu2+, and one Ga3+ atom. In the sixth F1- site, F1- is bonded in a 4-coordinate geometry to two Na1+, one Cu2+, and one Ga3+ atom. In the seventh F1- site, F1- is bonded to three Na1+ and one Ga3+ atom to form a mixture of distorted edge and corner-sharing FNa3Ga tetrahedra.