Materials Data on ErAgSe2 by Materials Project

Abstract

AgErSe2 is Caswellsilverite-like structured and crystallizes in the tetragonal I4_1/amd space group. The structure is three-dimensional. Er3+ is bonded to six Se2- atoms to form ErSe6 octahedra that share corners with two equivalent AgSe6 octahedra, corners with four equivalent ErSe6 octahedra, edges with four equivalent ErSe6 octahedra, and edges with eight equivalent AgSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–7°. There are four shorter (2.85 Å) and two longer (2.86 Å) Er–Se bond lengths. Ag1+ is bonded to six Se2- atoms to form AgSe6 octahedra that share corners with two equivalent ErSe6 octahedra, corners with four equivalent AgSe6 octahedra, edges with four equivalent AgSe6 octahedra, and edges with eight equivalent ErSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–7°. There are four shorter (2.85 Å) and two longer (3.19 Å) Ag–Se bond lengths. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to three equivalent Er3+ and three equivalent Ag1+ atoms to form a mixture of edge and corner-sharing SeEr3Ag3 octahedra. The corner-sharing octahedra tilt angles range from 0–7°. In the second Se2- site, Se2- is bonded to three equivalent Er3+ and three equivalent Ag1+ atoms to form a mixture of edge and corner-sharing SeEr3Ag3 octahedra. The corner-sharing octahedra tilt angles range from 0–7°. In the third Se2- site, Se2- is bonded to three equivalent Er3+ and three equivalent Ag1+ atoms to form a mixture of edge and corner-sharing SeEr3Ag3 octahedra. The corner-sharing octahedra tilt angles range from 0–7°. There are two shorter (2.85 Å) and one longer (2.86 Å) Se–Er bond lengths. In the fourth Se2- site, Se2- is bonded to three equivalent Er3+ and three equivalent Ag1+ atoms to form a mixture of edge and corner-sharing SeEr3Ag3 octahedra. The corner-sharing octahedra tilt angles range from 0–7°. There are two shorter (2.85 Å) and one longer (2.86 Å) Se–Er bond lengths.