RR spectra from TD-DFT. To compute the resonance Raman spectra for thymine we adopted the following computational strategy. First, to determine the solvation structure around thymine we used Autosolvate to create microsolvated cluster structures. Using a two-layer ONIOM, we performed a preliminary analysis of the normal modes of the microsolvated thymine. In the ONIOM analysis the molecule was treated at a quantum mechanical (QM) level while the solvent was captured through a classical force field. For the QM computation we used Density Functional Theory (DFT) with the PBE0 functional and 6-311+G(d,p) as a basis. The normal mode analysis revealed four water molecules that most strongly couple to the molecule. The geometry of the thymine and the 4 water molecules were then optimized using DFT using both PBE0/6-311+G(d,p) and CAM-B3LYP/6-311+G(d,p). The overall dielectric environment was captured through a self-consistent reaction field (SCRF) as the polarizable continuum model. The XYZ coordinates of the optimized geometries are shown in Table and. Using these structures, the resonance Raman spectra for thymine was computed using the vertical gradient approach. Ground state potential energy surfaces were determined through DFT while electronic transitions and excited-state gradients through time-dependent DFT. The solvent was captured through the SCRF and the four explicit water molecules. The spectra was computed using both PBE0/6-311+G(d,p) and CAM-B3LYP/6-311+G(d,p). The computed frequencies and Huang-Rhys factors for the 75 normal modes in the complex are included in Table . All computations were done using the Gaussian 16 simulation package. Figure compares the computed RR spectra with the experimental results in Ref. .