CaB2H2 crystallizes in the orthorhombic Pnma space group. Ca(1) is bonded in a 10-coordinate geometry to one B(1), four equivalent B(2), one H(1), and four equivalent H(2) atoms. There are two inequivalent B sites. In the first B site, B(1) is bonded in a distorted single-bond geometry to one Ca(1), one H(1), and two equivalent H(2) atoms. In the second B site, B(2) is bonded in a distorted single-bond geometry to four equivalent Ca(1) and one H(1) atom. There are two inequivalent H sites. In the first H site, H(1) is bonded in a 3-coordinate geometry to one Ca(1), one B(1), and one B(2) atom. In the second H site, H(2) is bonded to four equivalent Ca(1) and two equivalent B(1) atoms to form a mixture of distorted corner, face, and edge-sharing HCa4B2 octahedra. The corner-sharing octahedral tilt angles are 77°.
CaB2H2 crystallizes in the orthorhombic Pnma space group. Ca(1) is bonded in a 10-coordinate geometry to one B(1), four equivalent B(2), one H(1), and four equivalent H(2) atoms. The Ca(1)-B(1) bond length is 2.69 Å. There are a spread of Ca(1)-B(2) bond distances ranging from 2.66-2.69 Å. The Ca(1)-H(1) bond length is 2.23 Å. There are two shorter (2.65 Å) and two longer (2.72 Å) Ca(1)-H(2) bond lengths. There are two inequivalent B sites. In the first B site, B(1) is bonded in a distorted single-bond geometry to one Ca(1), one H(1), and two equivalent H(2) atoms. The B(1)-H(1) bond length is 1.40 Å. Both B(1)-H(2) bond lengths are 1.79 Å. In the second B site, B(2) is bonded in a distorted single-bond geometry to four equivalent Ca(1) and one H(1) atom. The B(2)-H(1) bond length is 1.25 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded in a 3-coordinate geometry to one Ca(1), one B(1), and one B(2) atom. In the second H site, H(2) is bonded to four equivalent Ca(1) and two equivalent B(1) atoms to form a mixture of distorted corner, face, and edge-sharing HCa4B2 octahedra. The corner-sharing octahedral tilt angles are 77°.