Sr3TaCoO7 is (La,Ba)CuO4-derived structured and crystallizes in the tetragonal I4_1cd space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to four equivalent O(3) and four equivalent O(4) atoms. In the second Sr site, Sr(2) is bonded in a 9-coordinate geometry to one O(1), four equivalent O(2), and four equivalent O(5) atoms. In the third Sr site, Sr(3) is bonded in a 9-coordinate geometry to one O(2), four equivalent O(1), and four equivalent O(4) atoms. Ta(1) is bonded to one O(2), one O(3), and four equivalent O(5) atoms to form TaO6 octahedra that share  a cornercorner with one Co(1)O6 octahedra and corners with four equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-6°. Co(1) is bonded to one O(1), one O(3), and four equivalent O(4) atoms to form distorted CoO6 octahedra that share  a cornercorner with one Ta(1)O6 octahedra and corners with four equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-11°. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Sr(2), four equivalent Sr(3), and one Co(1) atom to form distorted OSr5Co octahedra that share corners with four equivalent O(1)Sr5Co octahedra, corners with eight equivalent O(4)Sr4Co2 octahedra, edges with four equivalent O(1)Sr5Co octahedra, edges with four equivalent O(2)Sr5Ta octahedra, and faces with four equivalent O(4)Sr4Co2 octahedra. The corner-sharing octahedral tilt angles range from 14-55°. In the second O site, O(2) is bonded to one Sr(3), four equivalent Sr(2), and one Ta(1) atom to form OSr5Ta octahedra that share corners with four equivalent O(4)Sr4Co2 octahedra, corners with four equivalent O(2)Sr5Ta octahedra, edges with four equivalent O(1)Sr5Co octahedra, and edges with four equivalent O(2)Sr5Ta octahedra. The corner-sharing octahedral tilt angles range from 2-47°. In the third O site, O(3) is bonded in a distorted single-bond geometry to four equivalent Sr(1), one Ta(1), and one Co(1) atom. In the fourth O site, O(4) is bonded to two equivalent Sr(1), two equivalent Sr(3), and two equivalent Co(1) atoms to form distorted OSr4Co2 octahedra that share corners with two equivalent O(4)Sr4Co2 octahedra, corners with two equivalent O(2)Sr5Ta octahedra, corners with four equivalent O(1)Sr5Co octahedra, edges with two equivalent O(4)Sr4Co2 octahedra, faces with two equivalent O(1)Sr5Co octahedra, and faces with four equivalent O(4)Sr4Co2 octahedra. The corner-sharing octahedral tilt angles range from 11-55°. In the fifth O site, O(5) is bonded in a distorted linear geometry to two equivalent Sr(2) and two equivalent Ta(1) atoms.
Sr3TaCoO7 is (La,Ba)CuO4-derived structured and crystallizes in the tetragonal I4_1cd space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to four equivalent O(3) and four equivalent O(4) atoms. All Sr(1)-O(3) bond lengths are 2.86 Å. All Sr(1)-O(4) bond lengths are 2.59 Å. In the second Sr site, Sr(2) is bonded in a 9-coordinate geometry to one O(1), four equivalent O(2), and four equivalent O(5) atoms. The Sr(2)-O(1) bond length is 2.35 Å. All Sr(2)-O(2) bond lengths are 2.80 Å. All Sr(2)-O(5) bond lengths are 2.77 Å. In the third Sr site, Sr(3) is bonded in a 9-coordinate geometry to one O(2), four equivalent O(1), and four equivalent O(4) atoms. The Sr(3)-O(2) bond length is 2.65 Å. All Sr(3)-O(1) bond lengths are 2.82 Å. All Sr(3)-O(4) bond lengths are 2.71 Å. Ta(1) is bonded to one O(2), one O(3), and four equivalent O(5) atoms to form TaO6 octahedra that share  a cornercorner with one Co(1)O6 octahedra and corners with four equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-6°. The Ta(1)-O(2) bond length is 2.08 Å. The Ta(1)-O(3) bond length is 1.92 Å. All Ta(1)-O(5) bond lengths are 1.98 Å. Co(1) is bonded to one O(1), one O(3), and four equivalent O(4) atoms to form distorted CoO6 octahedra that share  a cornercorner with one Ta(1)O6 octahedra and corners with four equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-11°. The Co(1)-O(1) bond length is 2.00 Å. The Co(1)-O(3) bond length is 2.43 Å. There are two shorter (1.89 Å) and two longer (2.09 Å) Co(1)-O(4) bond lengths. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Sr(2), four equivalent Sr(3), and one Co(1) atom to form distorted OSr5Co octahedra that share corners with four equivalent O(1)Sr5Co octahedra, corners with eight equivalent O(4)Sr4Co2 octahedra, edges with four equivalent O(1)Sr5Co octahedra, edges with four equivalent O(2)Sr5Ta octahedra, and faces with four equivalent O(4)Sr4Co2 octahedra. The corner-sharing octahedral tilt angles range from 14-55°. In the second O site, O(2) is bonded to one Sr(3), four equivalent Sr(2), and one Ta(1) atom to form OSr5Ta octahedra that share corners with four equivalent O(4)Sr4Co2 octahedra, corners with four equivalent O(2)Sr5Ta octahedra, edges with four equivalent O(1)Sr5Co octahedra, and edges with four equivalent O(2)Sr5Ta octahedra. The corner-sharing octahedral tilt angles range from 2-47°. In the third O site, O(3) is bonded in a distorted single-bond geometry to four equivalent Sr(1), one Ta(1), and one Co(1) atom. In the fourth O site, O(4) is bonded to two equivalent Sr(1), two equivalent Sr(3), and two equivalent Co(1) atoms to form distorted OSr4Co2 octahedra that share corners with two equivalent O(4)Sr4Co2 octahedra, corners with two equivalent O(2)Sr5Ta octahedra, corners with four equivalent O(1)Sr5Co octahedra, edges with two equivalent O(4)Sr4Co2 octahedra, faces with two equivalent O(1)Sr5Co octahedra, and faces with four equivalent O(4)Sr4Co2 octahedra. The corner-sharing octahedral tilt angles range from 11-55°. In the fifth O site, O(5) is bonded in a distorted linear geometry to two equivalent Sr(2) and two equivalent Ta(1) atoms.