Materials Data on YbAlB4 by Materials Project

Abstract

YbAlB4 is hexagonal omega structure-derived structured and crystallizes in the orthorhombic Pmmm space group. The structure is three-dimensional. Yb3+ is bonded to twelve B+1.50- atoms to form YbB12 cuboctahedra that share edges with four equivalent YbB12 cuboctahedra, edges with eight equivalent AlB12 cuboctahedra, faces with four equivalent YbB12 cuboctahedra, and faces with four equivalent AlB12 cuboctahedra. There are four shorter (2.57 Å) and eight longer (2.58 Å) Yb–B bond lengths. Al3+ is bonded to twelve B+1.50- atoms to form AlB12 cuboctahedra that share edges with four equivalent AlB12 cuboctahedra, edges with eight equivalent YbB12 cuboctahedra, faces with four equivalent YbB12 cuboctahedra, and faces with four equivalent AlB12 cuboctahedra. There are four shorter (2.48 Å) and eight longer (2.54 Å) Al–B bond lengths. There are two inequivalent B+1.50- sites. In the first B+1.50- site, B+1.50- is bonded in a 9-coordinate geometry to four equivalent Yb3+, two equivalent Al3+, and three B+1.50- atoms. There is two shorter (1.79 Å) and one longer (1.97 Å) B–B bond length. In the second B+1.50- site, B+1.50- is bonded in a 9-coordinate geometry to two equivalent Yb3+, four equivalent Al3+, and three B+1.50- atoms. The B–B bond length is 1.71 Å.