Sr2MoCu2AlO7 crystallizes in the monoclinic Cm space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(5), two equivalent O(7), and two equivalent O(8) atoms. In the second Sr site, Sr(2) is bonded in a 7-coordinate geometry to one O(2), one O(4), one O(6), two equivalent O(7), and two equivalent O(8) atoms. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), and two equivalent O(7) atoms. In the second Mo site, Mo(2) is bonded in a trigonal pyramidal geometry to one O(1), one O(2), and two equivalent O(8) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a rectangular see-saw-like geometry to one O(3), one O(4), one O(5), and one O(6) atom. In the second Cu site, Cu(2) is bonded in a rectangular see-saw-like geometry to one O(3), one O(4), one O(5), one O(6), and one O(7) atom. Al(1) is bonded in a distorted tetrahedral geometry to one O(3), one O(4), one O(5), and one O(6) atom. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), one Mo(1), and one Cu(2) atom. In the second O site, O(8) is bonded in a 5-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and one Mo(2) atom. In the third O site, O(1) is bonded in a distorted tetrahedral geometry to two equivalent Sr(1), one Mo(1), and one Mo(2) atom. In the fourth O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Sr(2), one Mo(1), and one Mo(2) atom. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to one Sr(1), one Cu(1), one Cu(2), and one Al(1) atom. In the sixth O site, O(4) is bonded in a 4-coordinate geometry to one Sr(2), one Cu(1), one Cu(2), and one Al(1) atom. In the seventh O site, O(5) is bonded in a 4-coordinate geometry to one Sr(1), one Cu(1), one Cu(2), and one Al(1) atom. In the eighth O site, O(6) is bonded in a 4-coordinate geometry to one Sr(2), one Cu(1), one Cu(2), and one Al(1) atom.
Sr2MoCu2AlO7 crystallizes in the monoclinic Cm space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(5), two equivalent O(7), and two equivalent O(8) atoms. The Sr(1)-O(1) bond length is 2.71 Å. The Sr(1)-O(3) bond length is 2.47 Å. The Sr(1)-O(5) bond length is 2.48 Å. There is one shorter (2.61 Å) and one longer (3.02 Å) Sr(1)-O(7) bond length. There is one shorter (2.65 Å) and one longer (2.98 Å) Sr(1)-O(8) bond length. In the second Sr site, Sr(2) is bonded in a 7-coordinate geometry to one O(2), one O(4), one O(6), two equivalent O(7), and two equivalent O(8) atoms. The Sr(2)-O(2) bond length is 2.66 Å. The Sr(2)-O(4) bond length is 2.48 Å. The Sr(2)-O(6) bond length is 2.48 Å. There is one shorter (2.72 Å) and one longer (2.90 Å) Sr(2)-O(7) bond length. There is one shorter (2.59 Å) and one longer (3.08 Å) Sr(2)-O(8) bond length. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), and two equivalent O(7) atoms. The Mo(1)-O(1) bond length is 2.03 Å. The Mo(1)-O(2) bond length is 2.49 Å. Both Mo(1)-O(7) bond lengths are 1.98 Å. In the second Mo site, Mo(2) is bonded in a trigonal pyramidal geometry to one O(1), one O(2), and two equivalent O(8) atoms. The Mo(2)-O(1) bond length is 2.06 Å. The Mo(2)-O(2) bond length is 1.94 Å. Both Mo(2)-O(8) bond lengths are 1.97 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a rectangular see-saw-like geometry to one O(3), one O(4), one O(5), and one O(6) atom. The Cu(1)-O(3) bond length is 2.00 Å. The Cu(1)-O(4) bond length is 2.00 Å. The Cu(1)-O(5) bond length is 1.98 Å. The Cu(1)-O(6) bond length is 2.04 Å. In the second Cu site, Cu(2) is bonded in a rectangular see-saw-like geometry to one O(3), one O(4), one O(5), one O(6), and one O(7) atom. The Cu(2)-O(3) bond length is 1.98 Å. The Cu(2)-O(4) bond length is 2.04 Å. The Cu(2)-O(5) bond length is 2.01 Å. The Cu(2)-O(6) bond length is 2.02 Å. The Cu(2)-O(7) bond length is 2.75 Å. Al(1) is bonded in a distorted tetrahedral geometry to one O(3), one O(4), one O(5), and one O(6) atom. The Al(1)-O(3) bond length is 1.89 Å. The Al(1)-O(4) bond length is 1.86 Å. The Al(1)-O(5) bond length is 1.84 Å. The Al(1)-O(6) bond length is 1.80 Å. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), one Mo(1), and one Cu(2) atom. In the second O site, O(8) is bonded in a 5-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and one Mo(2) atom. In the third O site, O(1) is bonded in a distorted tetrahedral geometry to two equivalent Sr(1), one Mo(1), and one Mo(2) atom. In the fourth O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Sr(2), one Mo(1), and one Mo(2) atom. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to one Sr(1), one Cu(1), one Cu(2), and one Al(1) atom. In the sixth O site, O(4) is bonded in a 4-coordinate geometry to one Sr(2), one Cu(1), one Cu(2), and one Al(1) atom. In the seventh O site, O(5) is bonded in a 4-coordinate geometry to one Sr(1), one Cu(1), one Cu(2), and one Al(1) atom. In the eighth O site, O(6) is bonded in a 4-coordinate geometry to one Sr(2), one Cu(1), one Cu(2), and one Al(1) atom.