MgAlH5 crystallizes in the orthorhombic C222_1 space group. Mg(1) is bonded to two equivalent H(1) and four equivalent H(2) atoms to form MgH6 octahedra that share corners with four equivalent Mg(1)H6 octahedra, corners with four equivalent Al(1)H6 octahedra, and  an edgeedge with one Al(1)H6 octahedra. The corner-sharing octahedral tilt angles range from 41-57°. Al(1) is bonded to two equivalent H(1), two equivalent H(2), and two equivalent H(3) atoms to form AlH6 octahedra that share corners with two equivalent Al(1)H6 octahedra, corners with four equivalent Mg(1)H6 octahedra, and  an edgeedge with one Mg(1)H6 octahedra. The corner-sharing octahedral tilt angles range from 41-57°. There are three inequivalent H sites. In the first H site, H(1) is bonded in a bent 150 degrees geometry to one Mg(1) and one Al(1) atom. In the second H site, H(2) is bonded in a trigonal planar geometry to two equivalent Mg(1) and one Al(1) atom. In the third H site, H(3) is bonded in a bent 120 degrees geometry to two equivalent Al(1) atoms.
MgAlH5 crystallizes in the orthorhombic C222_1 space group. Mg(1) is bonded to two equivalent H(1) and four equivalent H(2) atoms to form MgH6 octahedra that share corners with four equivalent Mg(1)H6 octahedra, corners with four equivalent Al(1)H6 octahedra, and  an edgeedge with one Al(1)H6 octahedra. The corner-sharing octahedral tilt angles range from 41-57°. Both Mg(1)-H(1) bond lengths are 1.86 Å. There are two shorter (1.97 Å) and two longer (2.02 Å) Mg(1)-H(2) bond lengths. Al(1) is bonded to two equivalent H(1), two equivalent H(2), and two equivalent H(3) atoms to form AlH6 octahedra that share corners with two equivalent Al(1)H6 octahedra, corners with four equivalent Mg(1)H6 octahedra, and  an edgeedge with one Mg(1)H6 octahedra. The corner-sharing octahedral tilt angles range from 41-57°. Both Al(1)-H(1) bond lengths are 1.68 Å. Both Al(1)-H(2) bond lengths are 1.79 Å. Both Al(1)-H(3) bond lengths are 1.76 Å. There are three inequivalent H sites. In the first H site, H(1) is bonded in a bent 150 degrees geometry to one Mg(1) and one Al(1) atom. In the second H site, H(2) is bonded in a trigonal planar geometry to two equivalent Mg(1) and one Al(1) atom. In the third H site, H(3) is bonded in a bent 120 degrees geometry to two equivalent Al(1) atoms.