Materials Data on AlNiAg2F7 by Materials Project

NiAg2AlF7 crystallizes in the orthorhombic Imm2 space group. The structure is three-dimensional. Ni2+ is bonded to six F1- atoms to form NiF6 octahedra that share corners with two equivalent NiF6 octahedra, corners with four equivalent AlF6 octahedra, and edges with six AgF8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 35–50°. There are a spread of Ni–F bond distances ranging from 2.00–2.03 Å. There are two inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded to eight F1- atoms to form AgF8 hexagonal bipyramids that share corners with two equivalent AgF8 hexagonal bipyramids, corners with two equivalent AlF6 octahedra, edges with four equivalent AgF8 hexagonal bipyramids, edges with two equivalent AlF6 octahedra, and edges with four equivalent NiF6 octahedra. The corner-sharing octahedra tilt angles range from 49–50°. There are a spread of Ag–F bond distances ranging from 2.39–2.78 Å. In the second Ag1+ site, Ag1+ is bonded to eight F1- atoms to form distorted AgF8 hexagonal bipyramids that share edges with six AgF8 hexagonal bipyramids, edges with two equivalent NiF6 octahedra, and edges with four equivalent AlF6 octahedra. There are a spread of Ag–F bond distances ranging from 2.50–2.90 Å. Al3+ is bonded to six F1- atoms to form AlF6 octahedra that share corners with two equivalent AgF8 hexagonal bipyramids, corners with four equivalent NiF6 octahedra, and edges with six AgF8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 35°. There is four shorter (1.82 Å) and two longer (1.83 Å) Al–F bond length. There are six inequivalent F1- sites. In the first F1- site, F1- is bonded in a 4-coordinate geometry to three Ag1+ and one Al3+ atom. In the second F1- site, F1- is bonded in a 2-coordinate geometry to one Ni2+, two Ag1+, and one Al3+ atom. In the third F1- site, F1- is bonded in a 2-coordinate geometry to one Ni2+, two Ag1+, and one Al3+ atom. In the fourth F1- site, F1- is bonded in a 2-coordinate geometry to two equivalent Ni2+ and two equivalent Ag1+ atoms. In the fifth F1- site, F1- is bonded in a 4-coordinate geometry to three Ag1+ and one Al3+ atom. In the sixth F1- site, F1- is bonded in a 2-coordinate geometry to two equivalent Ni2+ and two equivalent Ag1+ atoms.