Materials Data on CdAg4Ge2S7 by Materials Project

Abstract

Ag4CdGe2S7 is Stannite-like structured and crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are four inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded to four S2- atoms to form AgS4 tetrahedra that share corners with two equivalent CdS4 tetrahedra, corners with five AgS4 tetrahedra, and corners with five GeS4 tetrahedra. There are a spread of Ag–S bond distances ranging from 2.52–2.67 Å. In the second Ag1+ site, Ag1+ is bonded to four S2- atoms to form AgS4 tetrahedra that share a cornercorner with one CdS4 tetrahedra, corners with five GeS4 tetrahedra, and corners with six AgS4 tetrahedra. There are a spread of Ag–S bond distances ranging from 2.55–2.61 Å. In the third Ag1+ site, Ag1+ is bonded to four S2- atoms to form AgS4 tetrahedra that share corners with two equivalent CdS4 tetrahedra, corners with four GeS4 tetrahedra, and corners with six AgS4 tetrahedra. There are a spread of Ag–S bond distances ranging from 2.53–2.60 Å. In the fourth Ag1+ site, Ag1+ is bonded to four S2- atoms to form AgS4 tetrahedra that share corners with three equivalent CdS4 tetrahedra, corners with four GeS4 tetrahedra, and corners with five AgS4 tetrahedra. There are a spread of Ag–S bond distances ranging from 2.53–2.69 Å. Cd2+ is bonded to four S2- atoms to form CdS4 tetrahedra that share corners with four GeS4 tetrahedra and corners with eight AgS4 tetrahedra. There are a spread of Cd–S bond distances ranging from 2.56–2.61 Å. There are two inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded to four S2- atoms to form GeS4 tetrahedra that share a cornercorner with one GeS4 tetrahedra, corners with three equivalent CdS4 tetrahedra, and corners with eight AgS4 tetrahedra. There are three shorter (2.25 Å) and one longer (2.32 Å) Ge–S bond lengths. In the second Ge4+ site, Ge4+ is bonded to four S2- atoms to form GeS4 tetrahedra that share a cornercorner with one CdS4 tetrahedra, a cornercorner with one GeS4 tetrahedra, and corners with ten AgS4 tetrahedra. There are a spread of Ge–S bond distances ranging from 2.21–2.40 Å. There are seven inequivalent S2- sites. In the first S2- site, S2- is bonded to two Ag1+, one Cd2+, and one Ge4+ atom to form corner-sharing SCdAg2Ge tetrahedra. In the second S2- site, S2- is bonded to two Ag1+, one Cd2+, and one Ge4+ atom to form distorted corner-sharing SCdAg2Ge trigonal pyramids. In the third S2- site, S2- is bonded to two Ag1+, one Cd2+, and one Ge4+ atom to form corner-sharing SCdAg2Ge tetrahedra. In the fourth S2- site, S2- is bonded to two Ag1+, one Cd2+, and one Ge4+ atom to form corner-sharing SCdAg2Ge tetrahedra. In the fifth S2- site, S2- is bonded to three Ag1+ and one Ge4+ atom to form corner-sharing SAg3Ge tetrahedra. In the sixth S2- site, S2- is bonded to two Ag1+ and two Ge4+ atoms to form corner-sharing SAg2Ge2 tetrahedra. In the seventh S2- site, S2- is bonded to three Ag1+ and one Ge4+ atom to form corner-sharing SAg3Ge tetrahedra.