To shed light on the issue of the QM/DIM approach in the Raman calculations, we calculate the nuclear derivatives of the polarizability through the finite-difference (FD) method based on classical turning points (CTP). Two vibrational modes are chosen: the ring breathing modes around 1020 and 1050 cm -1 (modes 11 and 12). As shown in Fig. , the pyridine nitrogen atom shows little participation in the vibrational pattern of mode 12 while it gets involved in that of mode 11 (the same for other artificially enhanced modes). As Eq. ( ) shows, the molecular electric polarizability α mn is related to the density matrix derivatives with respect to the external field and molecular dipole moment matrix. We can divide the value of α mn into four terms with respect to the atomic basis sets contributed by its two components: the Py molecule and Au cluster. As shown in Table , for mode 11, the Au cluster contributes 8.877 au to the final polarizability change, which largely cancels the other contributions; while the value (-0.519 au) is negligible for mode 12. This distinction could be understood from the vibrational motions of the pyridine. The nitrogen atom plays a major role in the vibration of the ring breathing mode 11 in Fig. (a) and changes the local fields exerted on the Au clusters, which requires the contribution from high-order nonlinear response terms, i.e., the hyperpolarizability-related terms of the Au atoms, to be incorporated. On the other hand, as the vibration of ring stretch mode 12 in Fig. ) is symmetric along the chosen z axis, there is no change in the polarizability of the Au cluster. Furthermore, there is no explicit contribution from the metal atoms to the Raman intensities in the current QM/DIM method, which can be revealed by comparing Eqs. ( ) and (28).