Materials Data on YBeCu4 by Materials Project
BeYCu4 crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Be is bonded in a 12-coordinate geometry to three equivalent Y and nine Cu atoms. All Be–Y bond lengths are 2.92 Å. There are six shorter (2.40 Å) and three longer (2.92 Å) Be–Cu bond lengths. Y is bonded in a 6-coordinate geometry to three equivalent Be and fifteen Cu atoms. There are three shorter (2.92 Å) and twelve longer (3.19 Å) Y–Cu bond lengths. There are two inequivalent Cu sites. In the first Cu site, Cu is bonded to three equivalent Be, three equivalent Y, and six equivalent Cu atoms to form distorted CuY3Be3Cu6 cuboctahedra that share corners with twelve equivalent CuY4Be2Cu6 cuboctahedra, edges with six equivalent CuY3Be3Cu6 cuboctahedra, and faces with twenty CuY3Be3Cu6 cuboctahedra. All Cu–Cu bond lengths are 2.45 Å. In the second Cu site, Cu is bonded to two equivalent Be, four equivalent Y, and six Cu atoms to form distorted CuY4Be2Cu6 cuboctahedra that share corners with twenty CuY3Be3Cu6 cuboctahedra, edges with ten equivalent CuY4Be2Cu6 cuboctahedra, and faces with sixteen CuY3Be3Cu6 cuboctahedra. There are two shorter (2.46 Å) and two longer (2.60 Å) Cu–Cu bond lengths.