RbAlH4 crystallizes in the orthorhombic Cmc2_1 space group. Rb(1) is bonded in a 8-coordinate geometry to one H(2), two equivalent H(3), two equivalent H(4), and three equivalent H(1) atoms. Al(1) is bonded to one H(1), one H(3), one H(4), and two equivalent H(2) atoms to form corner-sharing AlH5 trigonal bipyramids. There are four inequivalent H sites. In the first H site, H(1) is bonded in a distorted single-bond geometry to three equivalent Rb(1) and one Al(1) atom. In the second H site, H(2) is bonded in a linear geometry to one Rb(1) and two equivalent Al(1) atoms. In the third H site, H(3) is bonded in a distorted single-bond geometry to two equivalent Rb(1) and one Al(1) atom. In the fourth H site, H(4) is bonded in a distorted single-bond geometry to two equivalent Rb(1) and one Al(1) atom.
RbAlH4 crystallizes in the orthorhombic Cmc2_1 space group. Rb(1) is bonded in a 8-coordinate geometry to one H(2), two equivalent H(3), two equivalent H(4), and three equivalent H(1) atoms. The Rb(1)-H(2) bond length is 3.17 Å. Both Rb(1)-H(3) bond lengths are 2.89 Å. Both Rb(1)-H(4) bond lengths are 2.71 Å. There are two shorter (2.92 Å) and one longer (3.11 Å) Rb(1)-H(1) bond length. Al(1) is bonded to one H(1), one H(3), one H(4), and two equivalent H(2) atoms to form corner-sharing AlH5 trigonal bipyramids. The Al(1)-H(1) bond length is 1.63 Å. The Al(1)-H(3) bond length is 1.64 Å. The Al(1)-H(4) bond length is 1.62 Å. Both Al(1)-H(2) bond lengths are 1.91 Å. There are four inequivalent H sites. In the first H site, H(1) is bonded in a distorted single-bond geometry to three equivalent Rb(1) and one Al(1) atom. In the second H site, H(2) is bonded in a linear geometry to one Rb(1) and two equivalent Al(1) atoms. In the third H site, H(3) is bonded in a distorted single-bond geometry to two equivalent Rb(1) and one Al(1) atom. In the fourth H site, H(4) is bonded in a distorted single-bond geometry to two equivalent Rb(1) and one Al(1) atom.