Materials Data on MgB4O7 by Materials Project
MgB4O7 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. Mg2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Mg–O bond distances ranging from 2.00–2.32 Å. There are four inequivalent B3+ sites. In the first B3+ site, B3+ is bonded to four O2- atoms to form corner-sharing BO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.45–1.51 Å. In the second 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 third B3+ site, B3+ is bonded to four O2- atoms to form corner-sharing BO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.44–1.56 Å. In the fourth B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.36 Å) and two longer (1.39 Å) B–O bond length. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mg2+ and two B3+ atoms. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to two B3+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Mg2+ and two B3+ atoms. In the fourth O2- site, O2- is bonded in a trigonal planar geometry to one Mg2+ and two B3+ atoms. In the fifth O2- site, O2- is bonded in a trigonal planar geometry to one Mg2+ and two B3+ atoms. In the sixth O2- site, O2- is bonded in a trigonal planar geometry to one Mg2+ and two B3+ atoms. In the seventh O2- site, O2- is bonded in a bent 120 degrees geometry to two B3+ atoms.