The points where this occur are marked in blue at the inset of Figure . The relative energies are consistently between 8.9 and 9.1 eV what is close to our most accurate result of 8.6 eV at the CCSD(T) level of theory (for these points, in the range 65 < w < 98, ∆E ≈ 0.008w + 8.369 with residual of 0.003 eV). Therefore, we are able to obtain a relative energy close to the CCSD(T) state-specific calculation using a state-average NEVPT2 approach for a large range of weights. In other words, it is possible to reproduce accurate relative energies using a single set of orbitals and smaller computational resources. Moreover, the weights w and m for these points correlate almost linearly, with the increase of one causing the decrease of the other (w ≈ 221 -1.8m with residual of 1.1%). This behavior can be interpreted based on the multi-d -occupancy as a balance between orbitals that stabilize the 3d 10 -occupancy or stabilize the 3d 9 one. For instance, when m is large the 3d -orbitals are biased toward the 3d 10 -occupancy, while the ligand ones are biased toward the 3d 9 -occupancy. That way, although this good agreement can be in part via a bias cancellation, when both weights are the same m = w = 78.45% both groups of orbitals should have the lowest bias toward any occupancy.