Based on the analysis of Huang-Rhys factors, we identified that the most important tuning mode corresponds to the Fe-N breathing mode (ground-state frequency is 210 cm -1 ). Therefore, we calculated one-dimensional potential energy profiles for this mode for the two sets of range-separation parameters A and B. Interestingly, there is a prominent difference between both sets of obtained energy profiles as shown in Fig. . Most notably, the MLCT states (those with energy minima near Q = 0.0) shift to higher energies for the larger α, whereas the MC states (with a minimum at Q ∼ 0.8 bohr•(a.m.u.) 1/2 ) shift to lower energies. This already indicates that both sets of (α, ω) pairs could lead to different photodynamics due to the character of the lowest excited states, as it will be investigated next.