The third and final major step is the post-processing of the properties calculated in step two. The partial Hessian is mass-weighted and diagonalized to yield the vibrational frequencies and the corresponding normal modes. The dipole and polarizability gradients are mass-weighted, transformed using the eigenvectors from the diagonalization of the Hessian, and used to calculate the IR and Raman intensities, respectively. Then, normal modes that include vibrational motions between the core region and the environment, which look like translational or rotational motions of the core region, are discarded since they are not well described by the model. We refer to these vibrational motions as pseudo-translations and pseudo-rotations. Finally, the harmonic IR and Raman spectra are plotted using the vibrational frequencies and intensities of all structures convoluted with an appropriate broadening function.