BaReH9 crystallizes in the monoclinic P2_1/m space group. Ba(1) is bonded in a 14-coordinate geometry to two equivalent H(3), two equivalent H(4), two equivalent H(5), four equivalent H(2), and four equivalent H(6) atoms. Re(1) is bonded in a 7-coordinate geometry to one H(1), two equivalent H(2), two equivalent H(4), and two equivalent H(6) atoms. There are six inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one Re(1) atom. In the second H site, H(2) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and one Re(1) atom. In the third H site, H(3) is bonded in a single-bond geometry to two equivalent Ba(1) and one H(5) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one Ba(1) and one Re(1) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to two equivalent Ba(1) and one H(3) atom. In the sixth H site, H(6) is bonded in a 3-coordinate geometry to two equivalent Ba(1) and one Re(1) atom.
BaReH9 crystallizes in the monoclinic P2_1/m space group. Ba(1) is bonded in a 14-coordinate geometry to two equivalent H(3), two equivalent H(4), two equivalent H(5), four equivalent H(2), and four equivalent H(6) atoms. Both Ba(1)-H(3) bond lengths are 2.57 Å. Both Ba(1)-H(4) bond lengths are 2.94 Å. Both Ba(1)-H(5) bond lengths are 2.60 Å. There are two shorter (2.73 Å) and two longer (2.86 Å) Ba(1)-H(2) bond lengths. There are two shorter (2.67 Å) and two longer (2.87 Å) Ba(1)-H(6) bond lengths. Re(1) is bonded in a 7-coordinate geometry to one H(1), two equivalent H(2), two equivalent H(4), and two equivalent H(6) atoms. The Re(1)-H(1) bond length is 1.68 Å. Both Re(1)-H(2) bond lengths are 1.71 Å. Both Re(1)-H(4) bond lengths are 1.69 Å. Both Re(1)-H(6) bond lengths are 1.75 Å. There are six inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one Re(1) atom. In the second H site, H(2) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and one Re(1) atom. In the third H site, H(3) is bonded in a single-bond geometry to two equivalent Ba(1) and one H(5) atom. The H(3)-H(5) bond length is 0.78 Å. In the fourth H site, H(4) is bonded in a single-bond geometry to one Ba(1) and one Re(1) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to two equivalent Ba(1) and one H(3) atom. In the sixth H site, H(6) is bonded in a 3-coordinate geometry to two equivalent Ba(1) and one Re(1) atom.