Cs2ZnH4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 9-coordinate geometry to one H(2), two equivalent H(3), and six equivalent H(1) atoms. In the second Cs site, Cs(2) is bonded in a 9-coordinate geometry to two equivalent H(3), three equivalent H(2), and four equivalent H(1) atoms. Zn(1) is bonded in a tetrahedral geometry to one H(2), one H(3), and two equivalent H(1) atoms. There are three inequivalent H sites. In the first H site, H(1) is bonded in a distorted single-bond geometry to two equivalent Cs(2), three equivalent Cs(1), and one Zn(1) atom. In the second H site, H(2) is bonded in a distorted single-bond geometry to one Cs(1), three equivalent Cs(2), and one Zn(1) atom. In the third H site, H(3) is bonded in a distorted single-bond geometry to two equivalent Cs(1), two equivalent Cs(2), and one Zn(1) atom.
Cs2ZnH4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 9-coordinate geometry to one H(2), two equivalent H(3), and six equivalent H(1) atoms. The Cs(1)-H(2) bond length is 3.39 Å. Both Cs(1)-H(3) bond lengths are 3.22 Å. There are a spread of Cs(1)-H(1) bond distances ranging from 3.29-3.42 Å. In the second Cs site, Cs(2) is bonded in a 9-coordinate geometry to two equivalent H(3), three equivalent H(2), and four equivalent H(1) atoms. There is one shorter (3.11 Å) and one longer (3.23 Å) Cs(2)-H(3) bond length. There is one shorter (3.20 Å) and two longer (3.37 Å) Cs(2)-H(2) bond lengths. There are two shorter (3.08 Å) and two longer (3.22 Å) Cs(2)-H(1) bond lengths. Zn(1) is bonded in a tetrahedral geometry to one H(2), one H(3), and two equivalent H(1) atoms. The Zn(1)-H(2) bond length is 1.67 Å. The Zn(1)-H(3) bond length is 1.68 Å. Both Zn(1)-H(1) bond lengths are 1.68 Å. There are three inequivalent H sites. In the first H site, H(1) is bonded in a distorted single-bond geometry to two equivalent Cs(2), three equivalent Cs(1), and one Zn(1) atom. In the second H site, H(2) is bonded in a distorted single-bond geometry to one Cs(1), three equivalent Cs(2), and one Zn(1) atom. In the third H site, H(3) is bonded in a distorted single-bond geometry to two equivalent Cs(1), two equivalent Cs(2), and one Zn(1) atom.