DOE OSTI2020
CaAgSn crystallizes in the trigonal P3m1 space group. The structure is three-dimensional. there are three inequivalent Ca sites. In the first Ca site, Ca is bonded to six Ag and six Sn atoms to form a mixture of distorted face and edge-sharing CaAg6Sn6 cuboctahedra. There are three shorter (3.23 Å) and three longer (3.32 Å) Ca–Ag bond lengths. There are three shorter (3.38 Å) and three longer (3.46 Å) Ca–Sn bond lengths. In the second Ca site, Ca is bonded in a 12-coordinate geometry to six Ag and six Sn atoms. There are three shorter (3.49 Å) and three longer (3.51 Å) Ca–Ag bond lengths. There are three shorter (3.23 Å) and three longer (3.25 Å) Ca–Sn bond lengths. In the third Ca site, Ca is bonded to six Ag and six Sn atoms to form a mixture of distorted face and edge-sharing CaAg6Sn6 cuboctahedra. There are three shorter (3.21 Å) and three longer (3.41 Å) Ca–Ag bond lengths. There are three shorter (3.34 Å) and three longer (3.48 Å) Ca–Sn bond lengths. There are three inequivalent Ag sites. In the first Ag site, Ag is bonded in a 9-coordinate geometry to six Ca and three equivalent Sn atoms. All Ag–Sn bond lengths are 2.81 Å. In the second Ag site, Ag is bonded in a 9-coordinate geometry to six Ca and four Sn atoms. There are three shorter (2.84 Å) and one longer (3.48 Å) Ag–Sn bond lengths. In the third Ag site, Ag is bonded in a 10-coordinate geometry to six Ca and four Sn atoms. There are three shorter (2.85 Å) and one longer (3.39 Å) Ag–Sn bond lengths. There are three inequivalent Sn sites. In the first Sn site, Sn is bonded in a 10-coordinate geometry to six Ca, three equivalent Ag, and one Sn atom. The Sn–Sn bond length is 3.25 Å. In the second Sn site, Sn is bonded in a 10-coordinate geometry to six Ca, three equivalent Ag, and one Sn atom. In the third Sn site, Sn is bonded in a 11-coordinate geometry to six Ca and five Ag atoms.