Materials Data on CaB5H4O9 by Materials Project
(CaB5HO9)2(H2)3 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of four molecular hydrogen molecules and two CaB5HO9 sheets oriented in the (0, 1, 0) direction. In each CaB5HO9 sheet, Ca is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of Ca–O bond distances ranging from 2.50–2.79 Å. There are five inequivalent B sites. In the first B site, B is bonded to four O atoms to form corner-sharing BO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.44–1.53 Å. In the second B site, B is bonded in a trigonal planar geometry to three O atoms. There is one shorter (1.35 Å) and two longer (1.39 Å) B–O bond length. In the third B site, B is bonded in a trigonal planar geometry to three O atoms. There is two shorter (1.37 Å) and one longer (1.40 Å) B–O bond length. In the fourth B site, B is bonded to four O atoms to form corner-sharing BO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.44–1.51 Å. In the fifth B site, B is bonded in a trigonal planar geometry to three O atoms. There are a spread of B–O bond distances ranging from 1.35–1.42 Å. H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. There are nine inequivalent O sites. In the first O site, O is bonded in a bent 120 degrees geometry to one B and one H atom. In the second O site, O is bonded in a distorted bent 120 degrees geometry to one Ca and two B atoms. In the third O site, O is bonded in a distorted water-like geometry to two equivalent Ca and two B atoms. In the fourth O site, O is bonded in a bent 120 degrees geometry to one Ca and two B atoms. In the fifth O site, O is bonded in a bent 120 degrees geometry to two B atoms. In the sixth O site, O is bonded in a bent 120 degrees geometry to one Ca and two B atoms. In the seventh O site, O is bonded in a distorted bent 120 degrees geometry to two equivalent Ca and two B atoms. In the eighth O site, O is bonded in a bent 120 degrees geometry to two B atoms. In the ninth O site, O is bonded in a distorted bent 120 degrees geometry to one Ca and two B atoms.