K2LiAlH6 is (Cubic) Perovskite-derived structured and crystallizes in the trigonal R-3m space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to three equivalent H(1) and nine equivalent H(2) atoms to form KH12 cuboctahedra that share corners with three equivalent K(2)H12 cuboctahedra, corners with six equivalent K(1)H12 cuboctahedra, corners with three equivalent Li(1)H6 octahedra, faces with three equivalent K(1)H12 cuboctahedra, faces with four equivalent K(2)H12 cuboctahedra,  a faceface with one Al(1)H6 octahedra, faces with three equivalent Li(1)H6 octahedra, and faces with three equivalent Al(2)H6 octahedra. The corner-sharing octahedral tilt angles are 4°. In the second K site, K(2) is bonded to three equivalent H(2) and nine equivalent H(1) atoms to form KH12 cuboctahedra that share corners with three equivalent K(1)H12 cuboctahedra, corners with six equivalent K(2)H12 cuboctahedra, corners with three equivalent Al(2)H6 octahedra, faces with three equivalent K(2)H12 cuboctahedra, faces with four equivalent K(1)H12 cuboctahedra, faces with three equivalent Al(1)H6 octahedra, and faces with four equivalent Li(1)H6 octahedra. The corner-sharing octahedral tilt angles are 13°. Li(1) is bonded to three equivalent H(1) and three equivalent H(2) atoms to form LiH6 octahedra that share corners with three equivalent K(1)H12 cuboctahedra, corners with three equivalent Al(1)H6 octahedra, faces with three equivalent K(1)H12 cuboctahedra, faces with four equivalent K(2)H12 cuboctahedra, and  a faceface with one Al(2)H6 octahedra. The corner-sharing octahedral tilt angles are 5°. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to six equivalent H(1) atoms to form AlH6 octahedra that share corners with six equivalent Li(1)H6 octahedra, faces with two equivalent K(1)H12 cuboctahedra, and faces with six equivalent K(2)H12 cuboctahedra. The corner-sharing octahedral tilt angles are 5°. In the second Al site, Al(2) is bonded to six equivalent H(2) atoms to form AlH6 octahedra that share corners with six equivalent K(2)H12 cuboctahedra, faces with six equivalent K(1)H12 cuboctahedra, and faces with two equivalent Li(1)H6 octahedra. There are two inequivalent H sites. In the first H site, H(1) is bonded in a distorted linear geometry to one K(1), three equivalent K(2), one Li(1), and one Al(1) atom. In the second H site, H(2) is bonded in a distorted L-shaped geometry to one K(2), three equivalent K(1), one Li(1), and one Al(2) atom.
K2LiAlH6 is (Cubic) Perovskite-derived structured and crystallizes in the trigonal R-3m space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to three equivalent H(1) and nine equivalent H(2) atoms to form KH12 cuboctahedra that share corners with three equivalent K(2)H12 cuboctahedra, corners with six equivalent K(1)H12 cuboctahedra, corners with three equivalent Li(1)H6 octahedra, faces with three equivalent K(1)H12 cuboctahedra, faces with four equivalent K(2)H12 cuboctahedra,  a faceface with one Al(1)H6 octahedra, faces with three equivalent Li(1)H6 octahedra, and faces with three equivalent Al(2)H6 octahedra. The corner-sharing octahedral tilt angles are 4°. All K(1)-H(1) bond lengths are 2.83 Å. There are six shorter (2.78 Å) and three longer (2.80 Å) K(1)-H(2) bond lengths. In the second K site, K(2) is bonded to three equivalent H(2) and nine equivalent H(1) atoms to form KH12 cuboctahedra that share corners with three equivalent K(1)H12 cuboctahedra, corners with six equivalent K(2)H12 cuboctahedra, corners with three equivalent Al(2)H6 octahedra, faces with three equivalent K(2)H12 cuboctahedra, faces with four equivalent K(1)H12 cuboctahedra, faces with three equivalent Al(1)H6 octahedra, and faces with four equivalent Li(1)H6 octahedra. The corner-sharing octahedral tilt angles are 13°. All K(2)-H(2) bond lengths are 2.84 Å. There are six shorter (2.79 Å) and three longer (2.87 Å) K(2)-H(1) bond lengths. Li(1) is bonded to three equivalent H(1) and three equivalent H(2) atoms to form LiH6 octahedra that share corners with three equivalent K(1)H12 cuboctahedra, corners with three equivalent Al(1)H6 octahedra, faces with three equivalent K(1)H12 cuboctahedra, faces with four equivalent K(2)H12 cuboctahedra, and  a faceface with one Al(2)H6 octahedra. The corner-sharing octahedral tilt angles are 5°. All Li(1)-H(1) bond lengths are 2.02 Å. All Li(1)-H(2) bond lengths are 1.99 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to six equivalent H(1) atoms to form AlH6 octahedra that share corners with six equivalent Li(1)H6 octahedra, faces with two equivalent K(1)H12 cuboctahedra, and faces with six equivalent K(2)H12 cuboctahedra. The corner-sharing octahedral tilt angles are 5°. All Al(1)-H(1) bond lengths are 1.77 Å. In the second Al site, Al(2) is bonded to six equivalent H(2) atoms to form AlH6 octahedra that share corners with six equivalent K(2)H12 cuboctahedra, faces with six equivalent K(1)H12 cuboctahedra, and faces with two equivalent Li(1)H6 octahedra. All Al(2)-H(2) bond lengths are 1.75 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded in a distorted linear geometry to one K(1), three equivalent K(2), one Li(1), and one Al(1) atom. In the second H site, H(2) is bonded in a distorted L-shaped geometry to one K(2), three equivalent K(1), one Li(1), and one Al(2) atom.