Mg(BH4)2 crystallizes in the tetragonal I4_1/acd space group. The structure consists of a Mg(BH4)2 framework. Mg(1) is bonded to four equivalent H(1) and four equivalent H(2) atoms to form MgH8 hexagonal bipyramids that share edges with four equivalent B(1)H4 tetrahedra. B(1) is bonded to two equivalent H(1) and two equivalent H(2) atoms to form BH4 tetrahedra that share edges with two equivalent Mg(1)H8 hexagonal bipyramids. There are two inequivalent H sites. In the first H site, H(2) is bonded in an L-shaped geometry to one Mg(1) and one B(1) atom. In the second H site, H(1) is bonded in an L-shaped geometry to one Mg(1) and one B(1) atom.
Mg(BH4)2 crystallizes in the tetragonal I4_1/acd space group. The structure consists of a Mg(BH4)2 framework. Mg(1) is bonded to four equivalent H(1) and four equivalent H(2) atoms to form MgH8 hexagonal bipyramids that share edges with four equivalent B(1)H4 tetrahedra. All Mg(1)-H(1) bond lengths are 2.08 Å. All Mg(1)-H(2) bond lengths are 2.12 Å. B(1) is bonded to two equivalent H(1) and two equivalent H(2) atoms to form BH4 tetrahedra that share edges with two equivalent Mg(1)H8 hexagonal bipyramids. Both B(1)-H(1) bond lengths are 1.23 Å. Both B(1)-H(2) bond lengths are 1.22 Å. There are two inequivalent H sites. In the first H site, H(2) is bonded in an L-shaped geometry to one Mg(1) and one B(1) atom. In the second H site, H(1) is bonded in an L-shaped geometry to one Mg(1) and one B(1) atom.