KNa2AlH6 is Orthorhombic Perovskite-derived structured and crystallizes in the monoclinic P2_1 space group. K(1) is bonded in a 10-coordinate geometry to one H(3), one H(5), two equivalent H(4), two equivalent H(6), and four equivalent H(1) atoms. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 8-coordinate geometry to one H(4), one H(6), two equivalent H(2), two equivalent H(3), and two equivalent H(5) atoms. In the second Na site, Na(2) is bonded to one H(1), one H(2), one H(3), one H(4), one H(5), and one H(6) atom to form NaH6 octahedra that share corners with six equivalent Al(1)H6 octahedra. The corner-sharing octahedral tilt angles range from 14-27°. Al(1) is bonded to one H(1), one H(2), one H(3), one H(4), one H(5), and one H(6) atom to form AlH6 octahedra that share corners with six equivalent Na(2)H6 octahedra. The corner-sharing octahedral tilt angles range from 14-27°. There are six inequivalent H sites. In the first H site, H(1) is bonded in a 4-coordinate geometry to four equivalent K(1), one Na(2), and one Al(1) atom. In the second H site, H(2) is bonded to one Na(2), two equivalent Na(1), and one Al(1) atom to form distorted corner-sharing HNa3Al tetrahedra. In the third H site, H(3) is bonded in a 5-coordinate geometry to one K(1), one Na(2), two equivalent Na(1), and one Al(1) atom. In the fourth H site, H(4) is bonded in a 5-coordinate geometry to two equivalent K(1), one Na(1), one Na(2), and one Al(1) atom. In the fifth H site, H(5) is bonded in a 3-coordinate geometry to one K(1), one Na(2), two equivalent Na(1), and one Al(1) atom. In the sixth H site, H(6) is bonded in a 5-coordinate geometry to two equivalent K(1), one Na(1), one Na(2), and one Al(1) atom.
KNa2AlH6 is Orthorhombic Perovskite-derived structured and crystallizes in the monoclinic P2_1 space group. K(1) is bonded in a 10-coordinate geometry to one H(3), one H(5), two equivalent H(4), two equivalent H(6), and four equivalent H(1) atoms. The K(1)-H(3) bond length is 2.95 Å. The K(1)-H(5) bond length is 2.90 Å. There is one shorter (2.59 Å) and one longer (2.90 Å) K(1)-H(4) bond length. There is one shorter (2.59 Å) and one longer (2.82 Å) K(1)-H(6) bond length. There are a spread of K(1)-H(1) bond distances ranging from 2.65-3.03 Å. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 8-coordinate geometry to one H(4), one H(6), two equivalent H(2), two equivalent H(3), and two equivalent H(5) atoms. The Na(1)-H(4) bond length is 2.61 Å. The Na(1)-H(6) bond length is 2.68 Å. There is one shorter (2.38 Å) and one longer (2.49 Å) Na(1)-H(2) bond length. There is one shorter (2.48 Å) and one longer (2.65 Å) Na(1)-H(3) bond length. There is one shorter (2.47 Å) and one longer (2.71 Å) Na(1)-H(5) bond length. In the second Na site, Na(2) is bonded to one H(1), one H(2), one H(3), one H(4), one H(5), and one H(6) atom to form NaH6 octahedra that share corners with six equivalent Al(1)H6 octahedra. The corner-sharing octahedral tilt angles range from 14-27°. The Na(2)-H(1) bond length is 2.42 Å. The Na(2)-H(2) bond length is 2.15 Å. The Na(2)-H(3) bond length is 2.29 Å. The Na(2)-H(4) bond length is 2.25 Å. The Na(2)-H(5) bond length is 2.33 Å. The Na(2)-H(6) bond length is 2.25 Å. Al(1) is bonded to one H(1), one H(2), one H(3), one H(4), one H(5), and one H(6) atom to form AlH6 octahedra that share corners with six equivalent Na(2)H6 octahedra. The corner-sharing octahedral tilt angles range from 14-27°. The Al(1)-H(1) bond length is 1.81 Å. The Al(1)-H(2) bond length is 1.74 Å. The Al(1)-H(3) bond length is 1.79 Å. The Al(1)-H(4) bond length is 1.76 Å. The Al(1)-H(5) bond length is 1.78 Å. The Al(1)-H(6) bond length is 1.76 Å. There are six inequivalent H sites. In the first H site, H(1) is bonded in a 4-coordinate geometry to four equivalent K(1), one Na(2), and one Al(1) atom. In the second H site, H(2) is bonded to one Na(2), two equivalent Na(1), and one Al(1) atom to form distorted corner-sharing HNa3Al tetrahedra. In the third H site, H(3) is bonded in a 5-coordinate geometry to one K(1), one Na(2), two equivalent Na(1), and one Al(1) atom. In the fourth H site, H(4) is bonded in a 5-coordinate geometry to two equivalent K(1), one Na(1), one Na(2), and one Al(1) atom. In the fifth H site, H(5) is bonded in a 3-coordinate geometry to one K(1), one Na(2), two equivalent Na(1), and one Al(1) atom. In the sixth H site, H(6) is bonded in a 5-coordinate geometry to two equivalent K(1), one Na(1), one Na(2), and one Al(1) atom.