Sr3FeTaO7 is (La,Ba)CuO4-derived structured and crystallizes in the tetragonal I4mm 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(1) and four equivalent O(5) atoms. In the second Sr site, Sr(2) is bonded in a 9-coordinate geometry to one O(3), four equivalent O(2), and four equivalent O(4) atoms. In the third Sr site, Sr(3) is bonded in a 9-coordinate geometry to one O(4), four equivalent O(1), and four equivalent O(3) atoms. Ta(1) is bonded to one O(4), one O(5), and four equivalent O(2) atoms to form TaO6 octahedra that share  a cornercorner with one Fe(1)O6 octahedra and corners with four equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-5°. Fe(1) is bonded to one O(3), one O(5), and four equivalent O(1) atoms to form FeO6 octahedra that share  a cornercorner with one Ta(1)O6 octahedra and corners with four equivalent Fe(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 two equivalent Sr(1), two equivalent Sr(3), and two equivalent Fe(1) atoms to form distorted OSr4Fe2 octahedra that share corners with two equivalent O(1)Sr4Fe2 octahedra, corners with two equivalent O(4)Sr5Ta octahedra, corners with four equivalent O(3)Sr5Fe octahedra, edges with two equivalent O(1)Sr4Fe2 octahedra, faces with two equivalent O(3)Sr5Fe octahedra, and faces with four equivalent O(1)Sr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 11-53°. In the second O site, O(2) is bonded in a distorted linear geometry to two equivalent Sr(2) and two equivalent Ta(1) atoms. In the third O site, O(3) is bonded to one Sr(2), four equivalent Sr(3), and one Fe(1) atom to form distorted OSr5Fe octahedra that share corners with four equivalent O(3)Sr5Fe octahedra, corners with eight equivalent O(1)Sr4Fe2 octahedra, edges with four equivalent O(3)Sr5Fe octahedra, edges with four equivalent O(4)Sr5Ta octahedra, and faces with four equivalent O(1)Sr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 14-53°. In the fourth O site, O(4) is bonded to one Sr(3), four equivalent Sr(2), and one Ta(1) atom to form distorted OSr5Ta octahedra that share corners with four equivalent O(1)Sr4Fe2 octahedra, corners with four equivalent O(4)Sr5Ta octahedra, edges with four equivalent O(3)Sr5Fe octahedra, and edges with four equivalent O(4)Sr5Ta octahedra. The corner-sharing octahedral tilt angles range from 3-47°. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to four equivalent Sr(1), one Ta(1), and one Fe(1) atom.
Sr3FeTaO7 is (La,Ba)CuO4-derived structured and crystallizes in the tetragonal I4mm 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(1) and four equivalent O(5) atoms. All Sr(1)-O(1) bond lengths are 2.58 Å. All Sr(1)-O(5) bond lengths are 2.87 Å. In the second Sr site, Sr(2) is bonded in a 9-coordinate geometry to one O(3), four equivalent O(2), and four equivalent O(4) atoms. The Sr(2)-O(3) bond length is 2.35 Å. All Sr(2)-O(2) bond lengths are 2.76 Å. All Sr(2)-O(4) bond lengths are 2.82 Å. In the third Sr site, Sr(3) is bonded in a 9-coordinate geometry to one O(4), four equivalent O(1), and four equivalent O(3) atoms. The Sr(3)-O(4) bond length is 2.64 Å. All Sr(3)-O(1) bond lengths are 2.71 Å. All Sr(3)-O(3) bond lengths are 2.84 Å. Ta(1) is bonded to one O(4), one O(5), and four equivalent O(2) atoms to form TaO6 octahedra that share  a cornercorner with one Fe(1)O6 octahedra and corners with four equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-5°. The Ta(1)-O(4) bond length is 2.07 Å. The Ta(1)-O(5) bond length is 1.91 Å. All Ta(1)-O(2) bond lengths are 2.00 Å. Fe(1) is bonded to one O(3), one O(5), and four equivalent O(1) atoms to form FeO6 octahedra that share  a cornercorner with one Ta(1)O6 octahedra and corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-11°. The Fe(1)-O(3) bond length is 1.99 Å. The Fe(1)-O(5) bond length is 2.39 Å. All Fe(1)-O(1) bond lengths are 2.01 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1), two equivalent Sr(3), and two equivalent Fe(1) atoms to form distorted OSr4Fe2 octahedra that share corners with two equivalent O(1)Sr4Fe2 octahedra, corners with two equivalent O(4)Sr5Ta octahedra, corners with four equivalent O(3)Sr5Fe octahedra, edges with two equivalent O(1)Sr4Fe2 octahedra, faces with two equivalent O(3)Sr5Fe octahedra, and faces with four equivalent O(1)Sr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 11-53°. In the second O site, O(2) is bonded in a distorted linear geometry to two equivalent Sr(2) and two equivalent Ta(1) atoms. In the third O site, O(3) is bonded to one Sr(2), four equivalent Sr(3), and one Fe(1) atom to form distorted OSr5Fe octahedra that share corners with four equivalent O(3)Sr5Fe octahedra, corners with eight equivalent O(1)Sr4Fe2 octahedra, edges with four equivalent O(3)Sr5Fe octahedra, edges with four equivalent O(4)Sr5Ta octahedra, and faces with four equivalent O(1)Sr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 14-53°. In the fourth O site, O(4) is bonded to one Sr(3), four equivalent Sr(2), and one Ta(1) atom to form distorted OSr5Ta octahedra that share corners with four equivalent O(1)Sr4Fe2 octahedra, corners with four equivalent O(4)Sr5Ta octahedra, edges with four equivalent O(3)Sr5Fe octahedra, and edges with four equivalent O(4)Sr5Ta octahedra. The corner-sharing octahedral tilt angles range from 3-47°. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to four equivalent Sr(1), one Ta(1), and one Fe(1) atom.