where C lk and C * rk refers to the coefficient of molecular orbital k at the connecting sites l and r, ϵ k is the orbital energy of k th MO, ιη is related to imaginary part of the Green's function and the summation goes over all the molecular orbitals. While considering only the contribution from frontier orbitals, Eq 9 is written as is energetically much closer to the E F than all the others, the qualitative understanding of conductance may be further simplified to include just one orbital. Accordingly the spin-up and spin-down conductance is dominated by α-SOMO and β-SUMO, respectively, as