Sr2CuO4 is (La,Ba)CuO4 structured and crystallizes in the tetragonal I4/mmm space group. Sr(1) is bonded in a 9-coordinate geometry to four equivalent O(1) and five equivalent O(2) atoms. Cu(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form corner-sharing CuO6 octahedra. The corner-sharing octahedra are not tilted. There are two inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Sr(1) and two equivalent Cu(1) atoms to form OSr4Cu2 octahedra that share corners with two equivalent O(1)Sr4Cu2 octahedra, corners with twelve equivalent O(2)Sr5Cu octahedra, edges with two equivalent O(1)Sr4Cu2 octahedra, faces with four equivalent O(1)Sr4Cu2 octahedra, and faces with four equivalent O(2)Sr5Cu octahedra. The corner-sharing octahedral tilt angles range from 0-55°. In the second O site, O(2) is bonded to five equivalent Sr(1) and one Cu(1) atom to form distorted OSr5Cu octahedra that share corners with five equivalent O(2)Sr5Cu octahedra, corners with twelve equivalent O(1)Sr4Cu2 octahedra, edges with eight equivalent O(2)Sr5Cu octahedra, and faces with four equivalent O(1)Sr4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-55°.
Sr2CuO4 is (La,Ba)CuO4 structured and crystallizes in the tetragonal I4/mmm space group. Sr(1) is bonded in a 9-coordinate geometry to four equivalent O(1) and five equivalent O(2) atoms. All Sr(1)-O(1) bond lengths are 2.59 Å. There is one shorter (2.49 Å) and four longer (2.73 Å) Sr(1)-O(2) bond lengths. Cu(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form corner-sharing CuO6 octahedra. The corner-sharing octahedra are not tilted. Both Cu(1)-O(2) bond lengths are 1.92 Å. All Cu(1)-O(1) bond lengths are 1.93 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Sr(1) and two equivalent Cu(1) atoms to form OSr4Cu2 octahedra that share corners with two equivalent O(1)Sr4Cu2 octahedra, corners with twelve equivalent O(2)Sr5Cu octahedra, edges with two equivalent O(1)Sr4Cu2 octahedra, faces with four equivalent O(1)Sr4Cu2 octahedra, and faces with four equivalent O(2)Sr5Cu octahedra. The corner-sharing octahedral tilt angles range from 0-55°. In the second O site, O(2) is bonded to five equivalent Sr(1) and one Cu(1) atom to form distorted OSr5Cu octahedra that share corners with five equivalent O(2)Sr5Cu octahedra, corners with twelve equivalent O(1)Sr4Cu2 octahedra, edges with eight equivalent O(2)Sr5Cu octahedra, and faces with four equivalent O(1)Sr4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-55°.