DOE OSTI2020
Na2AgF4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Na1+ is bonded to six F1- atoms to form NaF6 octahedra that share corners with three equivalent AgF6 octahedra, corners with four equivalent NaF6 octahedra, edges with three equivalent AgF6 octahedra, and edges with four equivalent NaF6 octahedra. The corner-sharing octahedra tilt angles range from 10–72°. There are a spread of Na–F bond distances ranging from 2.28–2.46 Å. Ag2+ is bonded to six F1- atoms to form distorted AgF6 octahedra that share corners with six equivalent NaF6 octahedra, edges with two equivalent AgF6 octahedra, and edges with six equivalent NaF6 octahedra. The corner-sharing octahedra tilt angles range from 10–63°. There are a spread of Ag–F bond distances ranging from 2.13–2.82 Å. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded to three equivalent Na1+ and one Ag2+ atom to form FNa3Ag tetrahedra that share corners with seven equivalent FNa3Ag2 square pyramids, corners with seven equivalent FNa3Ag tetrahedra, and edges with three equivalent FNa3Ag2 square pyramids. In the second F1- site, F1- is bonded to three equivalent Na1+ and two equivalent Ag2+ atoms to form distorted FNa3Ag2 square pyramids that share corners with two equivalent FNa3Ag2 square pyramids, corners with seven equivalent FNa3Ag tetrahedra, edges with five equivalent FNa3Ag2 square pyramids, and edges with three equivalent FNa3Ag tetrahedra.