The MO diagram is given above. The orbitals in the blue box
are the frontier orbitals. They are neither strongly bonding, nor strongly antibonding, and in fact very strongly resemble the
frontier orbitals of an octahedral transition-metal complex. The e2’ and a1’ together are closely allied to the Oh t2g set, while the
e1” directly corresponds to the eg set. This accounts for the variable electron-count and allows for a variety of electron
configurations, including high- and low-spin variants of MnCp2.