Li2Sr4Ta2Al2N8O crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded in a 2-coordinate geometry to one N(3) and one O(1) atom. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 6-coordinate geometry to one N(1), one N(3), one N(4), two equivalent N(2), and one O(1) atom. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one N(3), two equivalent N(1), two equivalent N(2), two equivalent N(4), and one O(1) atom. Ta(1) is bonded to one N(1), one N(2), one N(3), and one N(4) atom to form TaN4 tetrahedra that share corners with four equivalent Al(1)N4 tetrahedra. Al(1) is bonded to one N(1), one N(2), one N(3), and one N(4) atom to form AlN4 tetrahedra that share corners with four equivalent Ta(1)N4 tetrahedra. There are four inequivalent N sites. In the first N site, N(4) is bonded in a 2-coordinate geometry to one Sr(1), two equivalent Sr(2), one Ta(1), and one Al(1) atom. In the second N site, N(1) is bonded in a 5-coordinate geometry to one Sr(1), two equivalent Sr(2), one Ta(1), and one Al(1) atom. In the third N site, N(2) is bonded in a 2-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), one Ta(1), and one Al(1) atom. In the fourth N site, N(3) is bonded in a 3-coordinate geometry to one Li(1), one Sr(1), one Sr(2), one Ta(1), and one Al(1) atom. O(1) is bonded in a distorted octahedral geometry to two equivalent Li(1), two equivalent Sr(1), and two equivalent Sr(2) atoms.
Li2Sr4Ta2Al2N8O crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded in a 2-coordinate geometry to one N(3) and one O(1) atom. The Li(1)-N(3) bond length is 2.13 Å. The Li(1)-O(1) bond length is 1.86 Å. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 6-coordinate geometry to one N(1), one N(3), one N(4), two equivalent N(2), and one O(1) atom. The Sr(1)-N(1) bond length is 2.75 Å. The Sr(1)-N(3) bond length is 2.65 Å. The Sr(1)-N(4) bond length is 2.70 Å. There is one shorter (2.76 Å) and one longer (2.98 Å) Sr(1)-N(2) bond length. The Sr(1)-O(1) bond length is 2.51 Å. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one N(3), two equivalent N(1), two equivalent N(2), two equivalent N(4), and one O(1) atom. The Sr(2)-N(3) bond length is 2.80 Å. There is one shorter (2.70 Å) and one longer (3.08 Å) Sr(2)-N(1) bond length. There is one shorter (2.72 Å) and one longer (3.27 Å) Sr(2)-N(2) bond length. There is one shorter (3.11 Å) and one longer (3.20 Å) Sr(2)-N(4) bond length. The Sr(2)-O(1) bond length is 2.95 Å. Ta(1) is bonded to one N(1), one N(2), one N(3), and one N(4) atom to form TaN4 tetrahedra that share corners with four equivalent Al(1)N4 tetrahedra. The Ta(1)-N(1) bond length is 1.96 Å. The Ta(1)-N(2) bond length is 1.94 Å. The Ta(1)-N(3) bond length is 1.93 Å. The Ta(1)-N(4) bond length is 1.95 Å. Al(1) is bonded to one N(1), one N(2), one N(3), and one N(4) atom to form AlN4 tetrahedra that share corners with four equivalent Ta(1)N4 tetrahedra. The Al(1)-N(1) bond length is 1.87 Å. The Al(1)-N(2) bond length is 1.88 Å. The Al(1)-N(3) bond length is 1.86 Å. The Al(1)-N(4) bond length is 1.89 Å. There are four inequivalent N sites. In the first N site, N(4) is bonded in a 2-coordinate geometry to one Sr(1), two equivalent Sr(2), one Ta(1), and one Al(1) atom. In the second N site, N(1) is bonded in a 5-coordinate geometry to one Sr(1), two equivalent Sr(2), one Ta(1), and one Al(1) atom. In the third N site, N(2) is bonded in a 2-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), one Ta(1), and one Al(1) atom. In the fourth N site, N(3) is bonded in a 3-coordinate geometry to one Li(1), one Sr(1), one Sr(2), one Ta(1), and one Al(1) atom. O(1) is bonded in a distorted octahedral geometry to two equivalent Li(1), two equivalent Sr(1), and two equivalent Sr(2) atoms.