Sr4MgV2Fe2(AsO3)2 crystallizes in the tetragonal P-4m2 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 As(1), two equivalent O(1), and two equivalent O(2) atoms. In the second Sr site, Sr(1) is bonded in a 8-coordinate geometry to four equivalent As(1), two equivalent O(1), and two equivalent O(2) atoms. In the third Sr site, Sr(2) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. Mg(1) is bonded in a 4-coordinate geometry to four equivalent O(3) atoms. V(1) is bonded to one As(1), one O(3), two equivalent O(1), and two equivalent O(2) atoms to form distorted VAsO5 square pyramids that share corners with four equivalent V(1)AsO5 square pyramids and corners with four equivalent Fe(1,2)As4 tetrahedra. Fe(1,2) is bonded to four equivalent As(1) atoms to form distorted FeAs4 tetrahedra that share corners with four equivalent V(1)AsO5 square pyramids; corners with four equivalent Fe(1,2)As4 tetrahedra; and edges with four equivalent Fe(1,2)As4 tetrahedra. As(1) is bonded in a 9-coordinate geometry to four equivalent Sr(1); one V(1); and four equivalent Fe(1,2) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1), two equivalent Sr(2), and two equivalent V(1) atoms to form a mixture of distorted corner, edge, and face-sharing OSr4V2 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded to two equivalent Sr(1), two equivalent Sr(2), and two equivalent V(1) atoms to form a mixture of distorted corner, edge, and face-sharing OSr4V2 octahedra. The corner-sharing octahedral tilt angles are 10°. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Sr(2), two equivalent Mg(1), and one V(1) atom.
Sr4MgV2Fe2(AsO3)2 crystallizes in the tetragonal P-4m2 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 As(1), two equivalent O(1), and two equivalent O(2) atoms. All Sr(1)-As(1) bond lengths are 3.21 Å. Both Sr(1)-O(1) bond lengths are 2.82 Å. Both Sr(1)-O(2) bond lengths are 2.70 Å. In the second Sr site, Sr(1) is bonded in a 8-coordinate geometry to four equivalent As(1), two equivalent O(1), and two equivalent O(2) atoms. All Sr(1)-As(1) bond lengths are 3.21 Å. Both Sr(1)-O(1) bond lengths are 2.82 Å. Both Sr(1)-O(2) bond lengths are 2.70 Å. In the third Sr site, Sr(2) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. The Sr(2)-O(3) bond length is 2.69 Å. Both Sr(2)-O(1) bond lengths are 2.43 Å. Both Sr(2)-O(2) bond lengths are 2.53 Å. Mg(1) is bonded in a 4-coordinate geometry to four equivalent O(3) atoms. All Mg(1)-O(3) bond lengths are 2.21 Å. V(1) is bonded to one As(1), one O(3), two equivalent O(1), and two equivalent O(2) atoms to form distorted VAsO5 square pyramids that share corners with four equivalent V(1)AsO5 square pyramids and corners with four equivalent Fe(1,2)As4 tetrahedra. The V(1)-As(1) bond length is 3.26 Å. The V(1)-O(3) bond length is 2.40 Å. Both V(1)-O(1) bond lengths are 2.06 Å. Both V(1)-O(2) bond lengths are 2.07 Å. Fe(1,2) is bonded to four equivalent As(1) atoms to form distorted FeAs4 tetrahedra that share corners with four equivalent V(1)AsO5 square pyramids; corners with four equivalent Fe(1,2)As4 tetrahedra; and edges with four equivalent Fe(1,2)As4 tetrahedra. All Fe(1,2)-As(1) bond lengths are 2.64 Å. As(1) is bonded in a 9-coordinate geometry to four equivalent Sr(1); one V(1); and four equivalent Fe(1,2) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1), two equivalent Sr(2), and two equivalent V(1) atoms to form a mixture of distorted corner, edge, and face-sharing OSr4V2 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded to two equivalent Sr(1), two equivalent Sr(2), and two equivalent V(1) atoms to form a mixture of distorted corner, edge, and face-sharing OSr4V2 octahedra. The corner-sharing octahedral tilt angles are 10°. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Sr(2), two equivalent Mg(1), and one V(1) atom.