Materials Data on Ba2Cd2As3 by Materials Project
Ba2Cd2As3 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to six As+2.67- atoms to form BaAs6 octahedra that share corners with six equivalent BaAs7 pentagonal bipyramids, corners with seven CdAs4 tetrahedra, edges with four equivalent BaAs6 octahedra, an edgeedge with one BaAs7 pentagonal bipyramid, edges with five CdAs4 tetrahedra, and a faceface with one BaAs7 pentagonal bipyramid. There are a spread of Ba–As bond distances ranging from 3.30–3.41 Å. In the second Ba2+ site, Ba2+ is bonded to seven As+2.67- atoms to form BaAs7 pentagonal bipyramids that share corners with six equivalent BaAs6 octahedra, corners with seven CdAs4 tetrahedra, an edgeedge with one BaAs6 octahedra, edges with four equivalent BaAs7 pentagonal bipyramids, edges with three CdAs4 tetrahedra, a faceface with one BaAs6 octahedra, and faces with three equivalent BaAs7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 36–53°. There are a spread of Ba–As bond distances ranging from 3.42–3.55 Å. There are two inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded to four As+2.67- atoms to form CdAs4 tetrahedra that share corners with three equivalent BaAs6 octahedra, corners with three equivalent BaAs7 pentagonal bipyramids, corners with four CdAs4 tetrahedra, edges with three equivalent BaAs6 octahedra, edges with two equivalent BaAs7 pentagonal bipyramids, and edges with two equivalent CdAs4 tetrahedra. The corner-sharing octahedra tilt angles range from 18–50°. There are a spread of Cd–As bond distances ranging from 2.76–2.93 Å. In the second Cd2+ site, Cd2+ is bonded to four As+2.67- atoms to form CdAs4 tetrahedra that share corners with four equivalent BaAs6 octahedra, corners with four equivalent BaAs7 pentagonal bipyramids, corners with four CdAs4 tetrahedra, edges with two equivalent BaAs6 octahedra, an edgeedge with one BaAs7 pentagonal bipyramid, and edges with three CdAs4 tetrahedra. The corner-sharing octahedra tilt angles range from 22–56°. There are a spread of Cd–As bond distances ranging from 2.77–2.96 Å. There are three inequivalent As+2.67- sites. In the first As+2.67- site, As+2.67- is bonded in a 8-coordinate geometry to six Ba2+, one Cd2+, and one As+2.67- atom. The As–As bond length is 2.53 Å. In the second As+2.67- site, As+2.67- is bonded in a 7-coordinate geometry to four Ba2+ and three Cd2+ atoms. In the third As+2.67- site, As+2.67- is bonded to three equivalent Ba2+ and four Cd2+ atoms to form distorted edge-sharing AsBa3Cd4 pentagonal bipyramids.