Moreover, we calculate the normal Raman scattering spectra of 4,4 -bipyridine (4,4 -BPy) in the gas phase, and in the proximity of Au 2057 and Ag 2057 with respect to the DFT XC functional PBE0 and B3LYP, respectively. Fig. and Fig. in SI show the calculated results, where the gas-phase Raman intensities are scaled by a factor of 20. It is noted that the spectra calculated with PBE0 and B3LYP are almost identical, indicating that the impact of functional on the spectra is small.