Sr2FeCu(PbO3)2 crystallizes in the orthorhombic Pnc2 space group. Sr(1) is bonded in a 9-coordinate geometry to one O(1), four equivalent O(2), and four equivalent O(3) atoms. Fe(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles are 1°. Cu(1) is bonded in a linear geometry to two equivalent O(1) atoms. Pb(1) is bonded in a 3-coordinate geometry to one O(2) and two equivalent O(1) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Sr(1), one Cu(1), and two equivalent Pb(1) atoms to form distorted OSrCuPb2 tetrahedra that share corners with two equivalent O(2)Sr4FePb octahedra, corners with four equivalent O(3)Sr4Fe2 octahedra, corners with three equivalent O(1)SrCuPb2 tetrahedra, and edges with two equivalent O(2)Sr4FePb octahedra. The corner-sharing octahedral tilt angles range from 37-91°. In the second O site, O(2) is bonded to four equivalent Sr(1), one Fe(1), and one Pb(1) atom to form distorted OSr4FePb octahedra that share corners with five equivalent O(2)Sr4FePb octahedra, corners with eight equivalent O(3)Sr4Fe2 octahedra, corners with two equivalent O(1)SrCuPb2 tetrahedra, edges with four equivalent O(2)Sr4FePb octahedra, edges with two equivalent O(1)SrCuPb2 tetrahedra, and faces with four equivalent O(3)Sr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 0-53°. In the third O site, O(3) is bonded to four equivalent Sr(1) and two equivalent Fe(1) atoms to form distorted OSr4Fe2 octahedra that share corners with two equivalent O(3)Sr4Fe2 octahedra, corners with eight equivalent O(2)Sr4FePb octahedra, corners with four equivalent O(1)SrCuPb2 tetrahedra, edges with two equivalent O(3)Sr4Fe2 octahedra, faces with four equivalent O(3)Sr4Fe2 octahedra, and faces with four equivalent O(2)Sr4FePb octahedra. The corner-sharing octahedral tilt angles range from 0-53°.
Sr2FeCu(PbO3)2 crystallizes in the orthorhombic Pnc2 space group. Sr(1) is bonded in a 9-coordinate geometry to one O(1), four equivalent O(2), and four equivalent O(3) atoms. The Sr(1)-O(1) bond length is 2.68 Å. There are a spread of Sr(1)-O(2) bond distances ranging from 2.81-2.87 Å. There are a spread of Sr(1)-O(3) bond distances ranging from 2.61-2.67 Å. Fe(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles are 1°. Both Fe(1)-O(2) bond lengths are 2.17 Å. All Fe(1)-O(3) bond lengths are 1.98 Å. Cu(1) is bonded in a linear geometry to two equivalent O(1) atoms. Both Cu(1)-O(1) bond lengths are 1.86 Å. Pb(1) is bonded in a 3-coordinate geometry to one O(2) and two equivalent O(1) atoms. The Pb(1)-O(2) bond length is 2.20 Å. There is one shorter (2.32 Å) and one longer (2.45 Å) Pb(1)-O(1) bond length. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Sr(1), one Cu(1), and two equivalent Pb(1) atoms to form distorted OSrCuPb2 tetrahedra that share corners with two equivalent O(2)Sr4FePb octahedra, corners with four equivalent O(3)Sr4Fe2 octahedra, corners with three equivalent O(1)SrCuPb2 tetrahedra, and edges with two equivalent O(2)Sr4FePb octahedra. The corner-sharing octahedral tilt angles range from 37-91°. In the second O site, O(2) is bonded to four equivalent Sr(1), one Fe(1), and one Pb(1) atom to form distorted OSr4FePb octahedra that share corners with five equivalent O(2)Sr4FePb octahedra, corners with eight equivalent O(3)Sr4Fe2 octahedra, corners with two equivalent O(1)SrCuPb2 tetrahedra, edges with four equivalent O(2)Sr4FePb octahedra, edges with two equivalent O(1)SrCuPb2 tetrahedra, and faces with four equivalent O(3)Sr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 0-53°. In the third O site, O(3) is bonded to four equivalent Sr(1) and two equivalent Fe(1) atoms to form distorted OSr4Fe2 octahedra that share corners with two equivalent O(3)Sr4Fe2 octahedra, corners with eight equivalent O(2)Sr4FePb octahedra, corners with four equivalent O(1)SrCuPb2 tetrahedra, edges with two equivalent O(3)Sr4Fe2 octahedra, faces with four equivalent O(3)Sr4Fe2 octahedra, and faces with four equivalent O(2)Sr4FePb octahedra. The corner-sharing octahedral tilt angles range from 0-53°.