Materials Data on CaAgAs by Materials Project
CaAgAs crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. Ca2+ is bonded to five As3- atoms to form distorted CaAs5 square pyramids that share corners with ten equivalent CaAs5 square pyramids, corners with six equivalent AgAs4 tetrahedra, edges with six equivalent CaAs5 square pyramids, and edges with six equivalent AgAs4 tetrahedra. There are one shorter (3.00 Å) and four longer (3.07 Å) Ca–As bond lengths. Ag1+ is bonded to four As3- atoms to form distorted AgAs4 tetrahedra that share corners with six equivalent CaAs5 square pyramids, corners with ten equivalent AgAs4 tetrahedra, edges with six equivalent CaAs5 square pyramids, and edges with two equivalent AgAs4 tetrahedra. There are two shorter (2.77 Å) and two longer (2.82 Å) Ag–As bond lengths. There are two inequivalent As3- sites. In the first As3- site, As3- is bonded in a 9-coordinate geometry to three equivalent Ca2+ and six equivalent Ag1+ atoms. In the second As3- site, As3- is bonded in a 9-coordinate geometry to six equivalent Ca2+ and three equivalent Ag1+ atoms.