The study of molecular vibrations, as probed by vibrational spectroscopy, provides a unique lens through which the intricacies of chemical systems can be unraveled. However, the complexity of molecular systems poses challenges in interpreting experimental vibrational spectra. Large molecular systems often contain thousands of overlapping signals, each corresponding to a different molecular vibration. In such cases, theoretical research and computational studies can complement experimental studies as interpretative tools at the molecular scale. Yet, the computational demands increase substantially for large molecular systems, ranging from thousands to potentially millions or even billions of atoms. This is especially true when quantum mechanics is essential, such as in simulations of chemical reactions and light-matter interactions. Existing computational methods based on molecular quantum mechanics face limitations, particularly when considering thermal effects. To address this challenge and significantly reduce computational costs, a multiscale quantum mechanics/molecular mechanics (QM/MM) approach is often employed. In this approach, the system is divided into a quantum core region modeled using quantum mechanics (QM) and a classical environment region described by an atomistic molecular mechanics (MM) force field. This is important for capturing anisotropic interactions, such as hydrogen bonds, between the two regions. For vibrational properties, these calculations provide invaluable insights into the chemical structure, bonding characteristics, and intermolecular interactions of these systems. If a static approach is used, i.e., where the atom positions are fixed in the property calculation, the environment description can be reduced to only include parameters that directly affect the core region. This can be referred to as a focused approach, as it only considers the full details of the core region and how it is affected by the environment. One such approach is the fragment-based polarizable embedding model (PE) 9,10 that will be the focus of this work. In Fig. , we demonstrate the application of it to a solute-solvent system, highlighting the partitioning into the core and environment regions. Various polarized embedding models, including the fragment-based PE model, have been applied for calculating analytical vibrational properties for different vibrational spectroscopies. In line with a focused approach, we implemented a PE-QM scheme utilizing the partial Hessian vibrational analysis (PHVA) approximation for the calculation of analytic vibrational properties to model harmonic IR and Raman spectra for large solute-solvent systems. Here, only the Hessian of the core region is used, while the off-diagonal blocks between the core and environment are disregarded, along with the diagonal block exclusive to the environment.