In the following, we introduce a scheme to quantify pseudo-translational and pseudo-rotational contributions in normal modes in the QM/MM-PHVA approach. Like in standard vibrational analysis, the partial Hessian is mass-weighted and diagonalized, yielding 3N eigenvectors and eigenvalues. Then, the solute is centered by translating its center of mass to the origin of the coordinate system, and the three (or two if the molecule is linear) principal axes of inertia I 1 , I 2 , and I 3 are determined. The principal axes of inertia are used to build vectors that describe rotation. The vectors corresponding to translations D 1 , D 2 , and D 3 of the αth 6 atom are defined as