Concretely speaking, we start from Eq. ( ), and solve Eq. ( ) to obtain |ψ ξ (t) . We then calculate the correlation function using Eq. ( ) and obtain the line shape function of spectra by Fourier transform of the correlation function. Finally, the corresponding absorption spectra of aggregates can be obtained by multiplying the lineshape functions with the absorption frequency. More detailed implementation for the calculations of the exciton dynamics processes and vibrationally resolved absorption spectra in an aggregate using Eq. ( ) can refer to Ref. 21, 22 and 23.