Cs4Mg3H10 crystallizes in the orthorhombic Cmce space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 11-coordinate geometry to one H(3), two equivalent H(4), four equivalent H(1), and four equivalent H(2) atoms. In the second Cs site, Cs(2) is bonded in a 10-coordinate geometry to one H(2), two equivalent H(4), three equivalent H(3), and four equivalent H(1) atoms. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one H(2), one H(3), two equivalent H(1), and two equivalent H(4) atoms to form a mixture of face and corner-sharing MgH6 octahedra. The corner-sharing octahedral tilt angles are 7°. In the second Mg site, Mg(2) is bonded to two equivalent H(3) and four equivalent H(1) atoms to form face-sharing MgH6 octahedra. There are four inequivalent H sites. In the first H site, H(2) is bonded in a distorted single-bond geometry to one Cs(2), four equivalent Cs(1), and one Mg(1) atom. In the second H site, H(3) is bonded in a 2-coordinate geometry to one Cs(1), three equivalent Cs(2), one Mg(1), and one Mg(2) atom. In the third H site, H(4) is bonded in a distorted linear geometry to two equivalent Cs(1), two equivalent Cs(2), and two equivalent Mg(1) atoms. In the fourth H site, H(1) is bonded in a distorted L-shaped geometry to two equivalent Cs(1), two equivalent Cs(2), one Mg(1), and one Mg(2) atom.
Cs4Mg3H10 crystallizes in the orthorhombic Cmce space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 11-coordinate geometry to one H(3), two equivalent H(4), four equivalent H(1), and four equivalent H(2) atoms. The Cs(1)-H(3) bond length is 3.32 Å. Both Cs(1)-H(4) bond lengths are 3.30 Å. There are two shorter (3.12 Å) and two longer (3.25 Å) Cs(1)-H(1) bond lengths. There are a spread of Cs(1)-H(2) bond distances ranging from 3.17-3.46 Å. In the second Cs site, Cs(2) is bonded in a 10-coordinate geometry to one H(2), two equivalent H(4), three equivalent H(3), and four equivalent H(1) atoms. The Cs(2)-H(2) bond length is 3.07 Å. Both Cs(2)-H(4) bond lengths are 3.15 Å. There is one shorter (3.02 Å) and two longer (3.14 Å) Cs(2)-H(3) bond lengths. There are two shorter (3.09 Å) and two longer (3.14 Å) Cs(2)-H(1) bond lengths. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one H(2), one H(3), two equivalent H(1), and two equivalent H(4) atoms to form a mixture of face and corner-sharing MgH6 octahedra. The corner-sharing octahedral tilt angles are 7°. The Mg(1)-H(2) bond length is 1.89 Å. The Mg(1)-H(3) bond length is 2.08 Å. Both Mg(1)-H(1) bond lengths are 2.07 Å. Both Mg(1)-H(4) bond lengths are 2.03 Å. In the second Mg site, Mg(2) is bonded to two equivalent H(3) and four equivalent H(1) atoms to form face-sharing MgH6 octahedra. Both Mg(2)-H(3) bond lengths are 1.97 Å. All Mg(2)-H(1) bond lengths are 1.97 Å. There are four inequivalent H sites. In the first H site, H(2) is bonded in a distorted single-bond geometry to one Cs(2), four equivalent Cs(1), and one Mg(1) atom. In the second H site, H(3) is bonded in a 2-coordinate geometry to one Cs(1), three equivalent Cs(2), one Mg(1), and one Mg(2) atom. In the third H site, H(4) is bonded in a distorted linear geometry to two equivalent Cs(1), two equivalent Cs(2), and two equivalent Mg(1) atoms. In the fourth H site, H(1) is bonded in a distorted L-shaped geometry to two equivalent Cs(1), two equivalent Cs(2), one Mg(1), and one Mg(2) atom.