where γ c is the bath characteristic frequency and λ c is the reorganization energy, then the integral in Eq. 12 can be analytically evaluated as R(ω) = ωJ c (ω)/γ c , which is later used in our numerical evaluation. The Markovian limit will be reached when γ c → ∞, hence R(ω) → 0, and the effective spectral density has a Brownian oscillator form 38