Materials Data on HoB4 by Materials Project
HoB4 crystallizes in the tetragonal P4/mbm space group. The structure is three-dimensional. Ho is bonded in a 4-coordinate geometry to eighteen B atoms. There are a spread of Ho–B bond distances ranging from 2.72–3.06 Å. There are three inequivalent B sites. In the first B site, B is bonded in a 1-coordinate geometry to four equivalent Ho and five B atoms. There is one shorter (1.63 Å) and four longer (1.75 Å) B–B bond length. In the second B site, B is bonded in a distorted trigonal planar geometry to six equivalent Ho and three B atoms. There is two shorter (1.71 Å) and one longer (1.74 Å) B–B bond length. In the third B site, B is bonded in a 9-coordinate geometry to four equivalent Ho and five B atoms. Both B–B bond lengths are 1.81 Å.