where γ ν = 200 cm -1 is the bath characteristic frequency, and λ ν is the reorganization energy. We further introduce the quantity η ν ≡ 2λ ν /(M γ ν ω b ) to characterize the bath friction strength. For the results presented in the main text, we use η ν = 0.1, which corresponds to the Kramers under-damped regime (or energy diffusionlimited regime) for the model molecular system we considered here. Detailed discussions can be found in Sec. VI of the Supplementary Material.