Sr2YTaCu2O7 crystallizes in the monoclinic Cm space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to one O(1), one O(3), one O(4), one O(5), one O(6), one 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(3), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. Y(1) is bonded in a body-centered cubic geometry to two equivalent O(3), two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(1), one O(2), and two equivalent O(7) atoms to form distorted corner-sharing TaO4 trigonal pyramids. In the second Ta site, Ta(2) is bonded to one O(1), one O(2), and two equivalent O(8) atoms to form distorted corner-sharing TaO4 trigonal pyramids. 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), and one O(6) atom. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a 3-coordinate geometry to one Sr(1), one Sr(2), and one Ta(1) atom. In the second O site, O(8) is bonded in a 4-coordinate geometry to one Sr(2), two equivalent Sr(1), and one Ta(2) atom. In the third O site, O(1) is bonded to two equivalent Sr(1), one Ta(1), and one Ta(2) atom to form distorted corner-sharing OSr2Ta2 trigonal pyramids. The corner-sharing octahedral tilt angles range from 36-51°. In the fourth O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Sr(2), one Ta(1), and one Ta(2) atom. In the fifth O site, O(3) is bonded to one Sr(1), one Sr(2), two equivalent Y(1), one Cu(1), and one Cu(2) atom to form distorted OSr2Y2Cu2 octahedra that share corners with two equivalent O(3)Sr2Y2Cu2 octahedra, corners with two equivalent O(4)Sr2Y2Cu2 octahedra, corners with two equivalent O(5)Sr2Y2Cu2 octahedra,  a cornercorner with one O(1)Sr2Ta2 trigonal pyramid, edges with three equivalent O(5)Sr2Y2Cu2 octahedra, and faces with two equivalent O(4)Sr2Y2Cu2 octahedra. The corner-sharing octahedral tilt angles range from 4-70°. In the sixth O site, O(4) is bonded to one Sr(1), one Sr(2), two equivalent Y(1), one Cu(1), and one Cu(2) atom to form distorted OSr2Y2Cu2 octahedra that share corners with two equivalent O(3)Sr2Y2Cu2 octahedra, corners with two equivalent O(4)Sr2Y2Cu2 octahedra, corners with two equivalent O(5)Sr2Y2Cu2 octahedra,  a cornercorner with one O(1)Sr2Ta2 trigonal pyramid, faces with two equivalent O(3)Sr2Y2Cu2 octahedra, and faces with two equivalent O(5)Sr2Y2Cu2 octahedra. The corner-sharing octahedral tilt angles range from 3-71°. In the seventh O site, O(5) is bonded to one Sr(1), one Sr(2), two equivalent Y(1), one Cu(1), and one Cu(2) atom to form distorted OSr2Y2Cu2 octahedra that share corners with two equivalent O(3)Sr2Y2Cu2 octahedra, corners with two equivalent O(4)Sr2Y2Cu2 octahedra, corners with two equivalent O(5)Sr2Y2Cu2 octahedra,  a cornercorner with one O(1)Sr2Ta2 trigonal pyramid, edges with three equivalent O(3)Sr2Y2Cu2 octahedra, and faces with two equivalent O(4)Sr2Y2Cu2 octahedra. The corner-sharing octahedral tilt angles range from 4-71°. In the eighth O site, O(6) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(2), two equivalent Y(1), one Cu(1), and one Cu(2) atom.
Sr2YTaCu2O7 crystallizes in the monoclinic Cm space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to one O(1), one O(3), one O(4), one O(5), one O(6), one O(7), and two equivalent O(8) atoms. The Sr(1)-O(1) bond length is 2.76 Å. The Sr(1)-O(3) bond length is 2.53 Å. The Sr(1)-O(4) bond length is 2.68 Å. The Sr(1)-O(5) bond length is 2.56 Å. The Sr(1)-O(6) bond length is 2.90 Å. The Sr(1)-O(7) bond length is 2.53 Å. There is one shorter (2.95 Å) and one longer (2.97 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(3), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. The Sr(2)-O(2) bond length is 2.98 Å. The Sr(2)-O(3) bond length is 2.70 Å. The Sr(2)-O(4) bond length is 2.56 Å. The Sr(2)-O(5) bond length is 2.86 Å. The Sr(2)-O(6) bond length is 2.63 Å. The Sr(2)-O(7) bond length is 2.66 Å. The Sr(2)-O(8) bond length is 2.62 Å. Y(1) is bonded in a body-centered cubic geometry to two equivalent O(3), two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms. There is one shorter (2.36 Å) and one longer (2.52 Å) Y(1)-O(3) bond length. There is one shorter (2.39 Å) and one longer (2.64 Å) Y(1)-O(4) bond length. There is one shorter (2.38 Å) and one longer (2.58 Å) Y(1)-O(5) bond length. There is one shorter (2.36 Å) and one longer (2.67 Å) Y(1)-O(6) bond length. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(1), one O(2), and two equivalent O(7) atoms to form distorted corner-sharing TaO4 trigonal pyramids. The Ta(1)-O(1) bond length is 2.04 Å. The Ta(1)-O(2) bond length is 1.99 Å. Both Ta(1)-O(7) bond lengths are 1.86 Å. In the second Ta site, Ta(2) is bonded to one O(1), one O(2), and two equivalent O(8) atoms to form distorted corner-sharing TaO4 trigonal pyramids. The Ta(2)-O(1) bond length is 2.01 Å. The Ta(2)-O(2) bond length is 1.99 Å. Both Ta(2)-O(8) bond lengths are 1.87 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 2.02 Å. The Cu(1)-O(4) bond length is 1.98 Å. The Cu(1)-O(5) bond length is 2.00 Å. The Cu(1)-O(6) bond length is 1.96 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), and one O(6) atom. The Cu(2)-O(3) bond length is 2.04 Å. The Cu(2)-O(4) bond length is 1.96 Å. The Cu(2)-O(5) bond length is 2.01 Å. The Cu(2)-O(6) bond length is 1.94 Å. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a 3-coordinate geometry to one Sr(1), one Sr(2), and one Ta(1) atom. In the second O site, O(8) is bonded in a 4-coordinate geometry to one Sr(2), two equivalent Sr(1), and one Ta(2) atom. In the third O site, O(1) is bonded to two equivalent Sr(1), one Ta(1), and one Ta(2) atom to form distorted corner-sharing OSr2Ta2 trigonal pyramids. The corner-sharing octahedral tilt angles range from 36-51°. In the fourth O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Sr(2), one Ta(1), and one Ta(2) atom. In the fifth O site, O(3) is bonded to one Sr(1), one Sr(2), two equivalent Y(1), one Cu(1), and one Cu(2) atom to form distorted OSr2Y2Cu2 octahedra that share corners with two equivalent O(3)Sr2Y2Cu2 octahedra, corners with two equivalent O(4)Sr2Y2Cu2 octahedra, corners with two equivalent O(5)Sr2Y2Cu2 octahedra,  a cornercorner with one O(1)Sr2Ta2 trigonal pyramid, edges with three equivalent O(5)Sr2Y2Cu2 octahedra, and faces with two equivalent O(4)Sr2Y2Cu2 octahedra. The corner-sharing octahedral tilt angles range from 4-70°. In the sixth O site, O(4) is bonded to one Sr(1), one Sr(2), two equivalent Y(1), one Cu(1), and one Cu(2) atom to form distorted OSr2Y2Cu2 octahedra that share corners with two equivalent O(3)Sr2Y2Cu2 octahedra, corners with two equivalent O(4)Sr2Y2Cu2 octahedra, corners with two equivalent O(5)Sr2Y2Cu2 octahedra,  a cornercorner with one O(1)Sr2Ta2 trigonal pyramid, faces with two equivalent O(3)Sr2Y2Cu2 octahedra, and faces with two equivalent O(5)Sr2Y2Cu2 octahedra. The corner-sharing octahedral tilt angles range from 3-71°. In the seventh O site, O(5) is bonded to one Sr(1), one Sr(2), two equivalent Y(1), one Cu(1), and one Cu(2) atom to form distorted OSr2Y2Cu2 octahedra that share corners with two equivalent O(3)Sr2Y2Cu2 octahedra, corners with two equivalent O(4)Sr2Y2Cu2 octahedra, corners with two equivalent O(5)Sr2Y2Cu2 octahedra,  a cornercorner with one O(1)Sr2Ta2 trigonal pyramid, edges with three equivalent O(3)Sr2Y2Cu2 octahedra, and faces with two equivalent O(4)Sr2Y2Cu2 octahedra. The corner-sharing octahedral tilt angles range from 4-71°. In the eighth O site, O(6) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(2), two equivalent Y(1), one Cu(1), and one Cu(2) atom.