Sr2CoO4 is (La,Ba)CuO4 structured and crystallizes in the orthorhombic Immm space group. Sr(1) is bonded in a 9-coordinate geometry to two equivalent O(2), two equivalent O(3), and five equivalent O(1) atoms. Co(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing CoO6 octahedra. The corner-sharing octahedra are not tilted. There are three inequivalent O sites. In the first O site, O(1) is bonded to five equivalent Sr(1) and one Co(1) atom to form distorted OSr5Co octahedra that share corners with five equivalent O(1)Sr5Co octahedra, corners with six equivalent O(2)Sr4Co2 octahedra, corners with six equivalent O(3)Sr4Co2 octahedra, edges with eight equivalent O(1)Sr5Co octahedra, faces with two equivalent O(2)Sr4Co2 octahedra, and faces with two equivalent O(3)Sr4Co2 octahedra. The corner-sharing octahedral tilt angles range from 0-57°. In the second O site, O(2) is bonded to four equivalent Sr(1) and two equivalent Co(1) atoms to form OSr4Co2 octahedra that share corners with two equivalent O(2)Sr4Co2 octahedra, corners with twelve equivalent O(1)Sr5Co octahedra, edges with two equivalent O(2)Sr4Co2 octahedra, faces with four equivalent O(3)Sr4Co2 octahedra, and faces with four equivalent O(1)Sr5Co octahedra. The corner-sharing octahedral tilt angles range from 0-57°. In the third O site, O(3) is bonded to four equivalent Sr(1) and two equivalent Co(1) atoms to form distorted OSr4Co2 octahedra that share corners with two equivalent O(3)Sr4Co2 octahedra, corners with twelve equivalent O(1)Sr5Co octahedra, edges with two equivalent O(3)Sr4Co2 octahedra, faces with four equivalent O(2)Sr4Co2 octahedra, and faces with four equivalent O(1)Sr5Co octahedra. The corner-sharing octahedral tilt angles range from 0-55°.
Sr2CoO4 is (La,Ba)CuO4 structured and crystallizes in the orthorhombic Immm space group. Sr(1) is bonded in a 9-coordinate geometry to two equivalent O(2), two equivalent O(3), and five equivalent O(1) atoms. Both Sr(1)-O(2) bond lengths are 2.60 Å. Both Sr(1)-O(3) bond lengths are 2.65 Å. There is one shorter (2.51 Å) and four longer (2.73 Å) Sr(1)-O(1) bond lengths. Co(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing CoO6 octahedra. The corner-sharing octahedra are not tilted. Both Co(1)-O(1) bond lengths are 1.97 Å. Both Co(1)-O(2) bond lengths are 1.96 Å. Both Co(1)-O(3) bond lengths are 1.89 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to five equivalent Sr(1) and one Co(1) atom to form distorted OSr5Co octahedra that share corners with five equivalent O(1)Sr5Co octahedra, corners with six equivalent O(2)Sr4Co2 octahedra, corners with six equivalent O(3)Sr4Co2 octahedra, edges with eight equivalent O(1)Sr5Co octahedra, faces with two equivalent O(2)Sr4Co2 octahedra, and faces with two equivalent O(3)Sr4Co2 octahedra. The corner-sharing octahedral tilt angles range from 0-57°. In the second O site, O(2) is bonded to four equivalent Sr(1) and two equivalent Co(1) atoms to form OSr4Co2 octahedra that share corners with two equivalent O(2)Sr4Co2 octahedra, corners with twelve equivalent O(1)Sr5Co octahedra, edges with two equivalent O(2)Sr4Co2 octahedra, faces with four equivalent O(3)Sr4Co2 octahedra, and faces with four equivalent O(1)Sr5Co octahedra. The corner-sharing octahedral tilt angles range from 0-57°. In the third O site, O(3) is bonded to four equivalent Sr(1) and two equivalent Co(1) atoms to form distorted OSr4Co2 octahedra that share corners with two equivalent O(3)Sr4Co2 octahedra, corners with twelve equivalent O(1)Sr5Co octahedra, edges with two equivalent O(3)Sr4Co2 octahedra, faces with four equivalent O(2)Sr4Co2 octahedra, and faces with four equivalent O(1)Sr5Co octahedra. The corner-sharing octahedral tilt angles range from 0-55°.