DOE OSTI2020
AgCrTiS4 crystallizes in the monoclinic P2/m space group. The structure is three-dimensional. Ti4+ is bonded to six S2- atoms to form TiS6 octahedra that share corners with eight equivalent AgS6 octahedra, edges with two equivalent TiS6 octahedra, and edges with four equivalent CrS6 octahedra. The corner-sharing octahedra tilt angles range from 46–47°. All Ti–S bond lengths are 2.44 Å. Cr3+ is bonded to six S2- atoms to form CrS6 octahedra that share corners with four equivalent AgS6 octahedra, edges with two equivalent CrS6 octahedra, edges with four equivalent TiS6 octahedra, and faces with two equivalent AgS6 octahedra. The corner-sharing octahedral tilt angles are 46°. There are four shorter (2.42 Å) and two longer (2.43 Å) Cr–S bond lengths. Ag1+ is bonded to six S2- atoms to form distorted AgS6 octahedra that share corners with four equivalent CrS6 octahedra, corners with eight equivalent TiS6 octahedra, edges with two equivalent AgS6 octahedra, and faces with two equivalent CrS6 octahedra. The corner-sharing octahedra tilt angles range from 46–47°. There are two shorter (2.67 Å) and four longer (2.77 Å) Ag–S bond lengths. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a rectangular see-saw-like geometry to two equivalent Ti4+, one Cr3+, and one Ag1+ atom. In the second S2- site, S2- is bonded in a 5-coordinate geometry to one Ti4+, two equivalent Cr3+, and two equivalent Ag1+ atoms.