CrMn(CO2)6 crystallizes in the orthorhombic Fdd2 space group. Cr(1) is bonded in an octahedral geometry to one O(11), one O(12), one O(3), one O(4), one O(7), and one O(8) atom. The Cr(1)-O(11) bond length is 1.97 Å. The Cr(1)-O(12) bond length is 1.98 Å. The Cr(1)-O(3) bond length is 1.97 Å. The Cr(1)-O(4) bond length is 1.97 Å. The Cr(1)-O(7) bond length is 1.97 Å. The Cr(1)-O(8) bond length is 1.97 Å. Mn(1) is bonded in a distorted pentagonal pyramidal geometry to one O(1), one O(10), one O(2), one O(5), one O(6), and one O(9) atom. The Mn(1)-O(1) bond length is 2.30 Å. The Mn(1)-O(10) bond length is 2.22 Å. The Mn(1)-O(2) bond length is 2.24 Å. The Mn(1)-O(5) bond length is 2.33 Å. The Mn(1)-O(6) bond length is 2.18 Å. The Mn(1)-O(9) bond length is 2.25 Å. There are six inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one O(1) and one O(3) atom. The C(1)-O(1) bond length is 1.23 Å. The C(1)-O(3) bond length is 1.26 Å. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one O(2) and one O(4) atom. The C(2)-O(2) bond length is 1.25 Å. The C(2)-O(4) bond length is 1.25 Å. In the third C site, C(3) is bonded in a distorted bent 120 degrees geometry to one O(5) and one O(7) atom. The C(3)-O(5) bond length is 1.22 Å. The C(3)-O(7) bond length is 1.29 Å. In the fourth C site, C(4) is bonded in a distorted bent 120 degrees geometry to one O(6) and one O(8) atom. The C(4)-O(6) bond length is 1.21 Å. The C(4)-O(8) bond length is 1.27 Å. In the fifth C site, C(5) is bonded in a distorted bent 120 degrees geometry to one O(11) and one O(9) atom. The C(5)-O(11) bond length is 1.28 Å. The C(5)-O(9) bond length is 1.23 Å. In the sixth C site, C(6) is bonded in a distorted bent 120 degrees geometry to one O(10) and one O(12) atom. The C(6)-O(10) bond length is 1.22 Å. The C(6)-O(12) bond length is 1.28 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Mn(1) and one C(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Mn(1) and one C(2) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Cr(1) and one C(1) atom. In the fourth O site, O(4) is bonded in a water-like geometry to one Cr(1) and one C(2) atom. In the fifth O site, O(5) is bonded in a distorted water-like geometry to one Mn(1) and one C(3) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Mn(1) and one C(4) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Cr(1) and one C(3) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Cr(1) and one C(4) atom. In the ninth O site, O(9) is bonded in a distorted bent 120 degrees geometry to one Mn(1) and one C(5) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Mn(1) and one C(6) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to one Cr(1) and one C(5) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one Cr(1) and one C(6) atom. Linkers: 48 [O]C(=O)C([O])=O. Metal clusters: 16 [Mn] ,16 [Cr]. The MOF has largest included sphere 9.98 A, density 0.81 g/cm3, surface area 3282.67 m2/g, accessible volume 0.90 cm3/g