Na3RhH6 crystallizes in the orthorhombic Pnma space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a 7-coordinate geometry to one H(2), two equivalent H(1), two equivalent H(3), and two equivalent H(4) atoms. In the second Na site, Na(2) is bonded in a 10-coordinate geometry to one H(1), two equivalent H(4), three equivalent H(2), and four equivalent H(3) atoms. In the third Na site, Na(3) is bonded in a 7-coordinate geometry to one H(1), two equivalent H(3), and four equivalent H(4) atoms. Rh(1) is bonded in an octahedral geometry to one H(1), one H(2), two equivalent H(3), and two equivalent H(4) atoms. There are four inequivalent H sites. In the first H site, H(1) is bonded in a 5-coordinate geometry to one Na(2), one Na(3), two equivalent Na(1), and one Rh(1) atom. In the second H site, H(2) is bonded in a 5-coordinate geometry to one Na(1), three equivalent Na(2), and one Rh(1) atom. In the third H site, H(3) is bonded to one Na(1), one Na(3), two equivalent Na(2), and one Rh(1) atom to form a mixture of distorted edge, corner, and face-sharing HNa4Rh square pyramids. In the fourth H site, H(4) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), two equivalent Na(3), and one Rh(1) atom.
Na3RhH6 crystallizes in the orthorhombic Pnma space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a 7-coordinate geometry to one H(2), two equivalent H(1), two equivalent H(3), and two equivalent H(4) atoms. The Na(1)-H(2) bond length is 2.13 Å. Both Na(1)-H(1) bond lengths are 2.61 Å. Both Na(1)-H(3) bond lengths are 2.30 Å. Both Na(1)-H(4) bond lengths are 2.52 Å. In the second Na site, Na(2) is bonded in a 10-coordinate geometry to one H(1), two equivalent H(4), three equivalent H(2), and four equivalent H(3) atoms. The Na(2)-H(1) bond length is 2.20 Å. Both Na(2)-H(4) bond lengths are 2.62 Å. There is one shorter (2.24 Å) and two longer (2.60 Å) Na(2)-H(2) bond lengths. There are two shorter (2.37 Å) and two longer (2.58 Å) Na(2)-H(3) bond lengths. In the third Na site, Na(3) is bonded in a 7-coordinate geometry to one H(1), two equivalent H(3), and four equivalent H(4) atoms. The Na(3)-H(1) bond length is 2.43 Å. Both Na(3)-H(3) bond lengths are 2.38 Å. There are two shorter (2.39 Å) and two longer (2.47 Å) Na(3)-H(4) bond lengths. Rh(1) is bonded in an octahedral geometry to one H(1), one H(2), two equivalent H(3), and two equivalent H(4) atoms. The Rh(1)-H(1) bond length is 1.65 Å. The Rh(1)-H(2) bond length is 1.64 Å. Both Rh(1)-H(3) bond lengths are 1.65 Å. Both Rh(1)-H(4) bond lengths are 1.67 Å. There are four inequivalent H sites. In the first H site, H(1) is bonded in a 5-coordinate geometry to one Na(2), one Na(3), two equivalent Na(1), and one Rh(1) atom. In the second H site, H(2) is bonded in a 5-coordinate geometry to one Na(1), three equivalent Na(2), and one Rh(1) atom. In the third H site, H(3) is bonded to one Na(1), one Na(3), two equivalent Na(2), and one Rh(1) atom to form a mixture of distorted edge, corner, and face-sharing HNa4Rh square pyramids. In the fourth H site, H(4) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), two equivalent Na(3), and one Rh(1) atom.