DOI: 10.17188/1192095
title: Materials Data on Yb2Cu4As3 by Materials Project

description: Yb2Cu4As3 crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. there are three inequivalent Yb+2.50+ sites. In the first Yb+2.50+ site, Yb+2.50+ is bonded to five As3- atoms to form distorted YbAs5 square pyramids that share corners with six YbAs6 pentagonal pyramids, corners with ten CuAs4 tetrahedra, edges with two equivalent YbAs6 pentagonal pyramids, edges with two equivalent YbAs5 square pyramids, and edges with eight CuAs4 tetrahedra. There are one shorter (2.81 Å) and four longer (2.90 Å) Yb–As bond lengths. In the second Yb+2.50+ site, Yb+2.50+ is bonded to six As3- atoms to form distorted YbAs6 pentagonal pyramids that share corners with four equivalent YbAs6 pentagonal pyramids, corners with two equivalent YbAs5 square pyramids, corners with twelve CuAs4 tetrahedra, edges with two equivalent YbAs6 pentagonal pyramids, edges with eight CuAs4 tetrahedra, and faces with two equivalent YbAs6 pentagonal pyramids. There are two shorter (3.02 Å) and four longer (3.17 Å) Yb–As bond lengths. In the third Yb+2.50+ site, Yb+2.50+ is bonded to six equivalent As3- atoms to form distorted YbAs6 pentagonal pyramids that share corners with six equivalent YbAs5 square pyramids, corners with twelve CuAs4 tetrahedra, edges with three equivalent YbAs5 square pyramids, edges with nine CuAs4 tetrahedra, and faces with two equivalent YbAs6 pentagonal pyramids. All Yb–As bond lengths are 3.06 Å. There are four inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded to four As3- atoms to form CuAs4 tetrahedra that share corners with two equivalent YbAs6 pentagonal pyramids, corners with two equivalent YbAs5 square pyramids, corners with twelve CuAs4 tetrahedra, edges with three YbAs6 pentagonal pyramids, edges with two equivalent YbAs5 square pyramids, and edges with three CuAs4 tetrahedra. There are a spread of Cu–As bond distances ranging from 2.48–2.59 Å. In the second Cu1+ site, Cu1+ is bonded to four As3- atoms to form CuAs4 tetrahedra that share corners with four YbAs6 pentagonal pyramids, corners with three equivalent YbAs5 square pyramids, corners with eight CuAs4 tetrahedra, edges with three YbAs6 pentagonal pyramids, an edgeedge with one YbAs5 square pyramid, and edges with four CuAs4 tetrahedra. There are a spread of Cu–As bond distances ranging from 2.40–2.54 Å. In the third Cu1+ site, Cu1+ is bonded in a trigonal planar geometry to three equivalent As3- atoms. All Cu–As bond lengths are 2.34 Å. In the fourth Cu1+ site, Cu1+ is bonded to four As3- atoms to form CuAs4 tetrahedra that share corners with eight YbAs6 pentagonal pyramids, corners with six CuAs4 tetrahedra, edges with two equivalent YbAs6 pentagonal pyramids, edges with two equivalent YbAs5 square pyramids, and edges with four equivalent CuAs4 tetrahedra. There are two shorter (2.42 Å) and two longer (2.55 Å) Cu–As bond lengths. There are three inequivalent As3- sites. In the first As3- site, As3- is bonded in a 9-coordinate geometry to four equivalent Yb+2.50+ and five Cu1+ atoms. In the second As3- site, As3- is bonded in a 9-coordinate geometry to three Yb+2.50+ and six Cu1+ atoms. In the third As3- site, As3- is bonded in a 9-coordinate geometry to four Yb+2.50+ and five Cu1+ atoms.