Materials Data on DyAgSe2 by Materials Project

Abstract

DyAgSe2 crystallizes in the tetragonal I4_1md space group. The structure is three-dimensional. Dy3+ is bonded to six Se2- atoms to form DySe6 octahedra that share corners with four equivalent DySe6 octahedra, corners with three equivalent AgSe5 trigonal bipyramids, edges with four equivalent DySe6 octahedra, and edges with six equivalent AgSe5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 9–10°. There are a spread of Dy–Se bond distances ranging from 2.85–2.90 Å. Ag1+ is bonded to five Se2- atoms to form AgSe5 trigonal bipyramids that share corners with three equivalent DySe6 octahedra, corners with eight equivalent AgSe5 trigonal bipyramids, and edges with six equivalent DySe6 octahedra. The corner-sharing octahedra tilt angles range from 0–75°. There are three shorter (2.85 Å) and two longer (2.93 Å) Ag–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to three equivalent Dy3+ and two equivalent Ag1+ atoms to form distorted SeDy3Ag2 trigonal bipyramids that share corners with three equivalent SeDy3Ag3 octahedra, corners with eight equivalent SeDy3Ag2 trigonal bipyramids, and edges with six equivalent SeDy3Ag3 octahedra. The corner-sharing octahedra tilt angles range from 0–75°. In the second Se2- site, Se2- is bonded to three equivalent Dy3+ and three equivalent Ag1+ atoms to form SeDy3Ag3 octahedra that share corners with four equivalent SeDy3Ag3 octahedra, corners with three equivalent SeDy3Ag2 trigonal bipyramids, edges with four equivalent SeDy3Ag3 octahedra, and edges with six equivalent SeDy3Ag2 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 9–11°.