Cr3O4 crystallizes in the triclinic P-1 space group. There are six inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form edge-sharing CrO6 octahedra. In the second Cr site, Cr(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of corner and edge-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 3-14°. In the third Cr site, Cr(3) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of corner and edge-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 3-14°. In the fourth Cr site, Cr(4) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of corner and edge-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 3-14°. In the fifth Cr site, Cr(5) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of corner and edge-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 3-14°. In the sixth Cr site, Cr(6) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form edge-sharing CrO6 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Cr(1), one Cr(3), one Cr(4), and one Cr(6) atom. In the second O site, O(2) is bonded in a see-saw-like geometry to one Cr(1), one Cr(2), one Cr(5), and one Cr(6) atom. In the third O site, O(3) is bonded to one Cr(2), one Cr(3), one Cr(4), one Cr(5), and one Cr(6) atom to form a mixture of corner and edge-sharing OCr5 square pyramids. In the fourth O site, O(4) is bonded to one Cr(1), one Cr(2), one Cr(3), one Cr(4), and one Cr(5) atom to form a mixture of corner and edge-sharing OCr5 square pyramids.
Cr3O4 crystallizes in the triclinic P-1 space group. There are six inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form edge-sharing CrO6 octahedra. Both Cr(1)-O(1) bond lengths are 2.05 Å. Both Cr(1)-O(2) bond lengths are 2.01 Å. Both Cr(1)-O(4) bond lengths are 2.01 Å. In the second Cr site, Cr(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of corner and edge-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 3-14°. Both Cr(2)-O(2) bond lengths are 2.05 Å. Both Cr(2)-O(3) bond lengths are 2.06 Å. Both Cr(2)-O(4) bond lengths are 2.08 Å. In the third Cr site, Cr(3) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of corner and edge-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 3-14°. Both Cr(3)-O(1) bond lengths are 2.05 Å. Both Cr(3)-O(3) bond lengths are 2.08 Å. Both Cr(3)-O(4) bond lengths are 2.06 Å. In the fourth Cr site, Cr(4) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of corner and edge-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 3-14°. Both Cr(4)-O(1) bond lengths are 2.08 Å. Both Cr(4)-O(3) bond lengths are 2.13 Å. Both Cr(4)-O(4) bond lengths are 2.51 Å. In the fifth Cr site, Cr(5) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of corner and edge-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 3-14°. Both Cr(5)-O(2) bond lengths are 2.08 Å. Both Cr(5)-O(3) bond lengths are 2.51 Å. Both Cr(5)-O(4) bond lengths are 2.13 Å. In the sixth Cr site, Cr(6) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form edge-sharing CrO6 octahedra. Both Cr(6)-O(1) bond lengths are 2.01 Å. Both Cr(6)-O(2) bond lengths are 2.05 Å. Both Cr(6)-O(3) bond lengths are 2.00 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Cr(1), one Cr(3), one Cr(4), and one Cr(6) atom. In the second O site, O(2) is bonded in a see-saw-like geometry to one Cr(1), one Cr(2), one Cr(5), and one Cr(6) atom. In the third O site, O(3) is bonded to one Cr(2), one Cr(3), one Cr(4), one Cr(5), and one Cr(6) atom to form a mixture of corner and edge-sharing OCr5 square pyramids. In the fourth O site, O(4) is bonded to one Cr(1), one Cr(2), one Cr(3), one Cr(4), and one Cr(5) atom to form a mixture of corner and edge-sharing OCr5 square pyramids.