Materials Data on Ho2Cu(BO2)8 by Materials Project
Ho2Cu(BO2)8 crystallizes in the orthorhombic Pbam space group. The structure is three-dimensional. Ho3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ho–O bond distances ranging from 2.28–2.47 Å. Cu2+ is bonded in an octahedral geometry to six O2- atoms. There are four shorter (1.99 Å) and two longer (2.44 Å) Cu–O bond lengths. There are three inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of B–O bond distances ranging from 1.35–1.40 Å. In the second B3+ site, B3+ is bonded in a tetrahedral geometry to four O2- atoms. There is two shorter (1.47 Å) and two longer (1.48 Å) B–O bond length. In the third B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.35 Å) and two longer (1.40 Å) B–O bond length. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Ho3+ and one B3+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Ho3+, one Cu2+, and one B3+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Ho3+ and two B3+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ho3+ and two B3+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cu2+ and two equivalent B3+ atoms.