Materials Data on AlCr4AgS8 by Materials Project

Abstract

Cr4AgAlS8 is Spinel-derived structured and crystallizes in the cubic F-43m space group. The structure is three-dimensional. Cr3+ is bonded to six S2- atoms to form CrS6 octahedra that share corners with three equivalent AgS4 tetrahedra, corners with three equivalent AlS4 tetrahedra, and edges with six equivalent CrS6 octahedra. There are three shorter (2.35 Å) and three longer (2.49 Å) Cr–S bond lengths. Ag1+ is bonded to four equivalent S2- atoms to form AgS4 tetrahedra that share corners with twelve equivalent CrS6 octahedra. The corner-sharing octahedral tilt angles are 59°. All Ag–S bond lengths are 2.45 Å. Al3+ is bonded to four equivalent S2- atoms to form AlS4 tetrahedra that share corners with twelve equivalent CrS6 octahedra. The corner-sharing octahedral tilt angles are 58°. All Al–S bond lengths are 2.33 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded to three equivalent Cr3+ and one Al3+ atom to form a mixture of distorted corner and edge-sharing SAlCr3 trigonal pyramids. In the second S2- site, S2- is bonded to three equivalent Cr3+ and one Ag1+ atom to form distorted SCr3Ag trigonal pyramids that share corners with twelve SAlCr3 trigonal pyramids and edges with three equivalent SCr3Ag trigonal pyramids.