To overcome these limitations, several methods have been developed to interpret the IR vibrational spectrum obtained from an MD trajectory . The prin-cipal modes analysis has been proposed in which the average mass-weighted normal modes and associated frequencies are calculated using the Hessian matrix or the covariances of Cartesian atomic velocities . Martinez et al. have developed an effective modes analysis, with the aim to decompose the IR spectrum as an approximate sum of effective modes contributions . These effective modes are defined as linear combinations of atomic displacements, similarly to the normal modes analysis, and in the zero temperature limit, the harmonic normal modes are recovered. Since IR and VCD peaks are located at the same frequencies, the identification of the effective modes from the IR absorption bands can be used as an interpretation tool for VCD as well.