The PHVA approach, using pure QM and MM methods, has shown promising results for local modes. These studies are encouraging for the focused QM/MM-PHVA approach, which also targets local modes within the QM subsystem. In our study, we assess the QM/MM-PHVA method, applying it to solute-solvent systems with small, rigid solutes. We also investigate the impact of expanding the QM subsystem by including selected solvent molecules. Our goal is to evaluate the errors introduced by the QM/MM-PHVA approximation on harmonic frequencies and the corresponding IR and Raman intensities. To achieve this, we computed full Hessians, dipole gradients, and polarizability gradients based on full QM calculations for several model systems. We can assess the errors from the PHVA by comparing the partial Hessian and property gradients to the full quantities. Subsequently, we will analyze the discrepancies introduced by the QM/MM approach by comparing partial Hessians obtained from full QM calculations to those derived from QM/MM calculations.