Moreover, we have utilized the Tamm-Dancoff approximation (TDA) and the Resolution of Identity (RI) approximation to accelerate the TD-LC-DFT calculations by considering RIJCOSX for the Coulomb integral and Hartree-Fock exchange as well as def2/J as an auxiliary basis set as implemented in the ORCA program. The same RI approximation was also employed together with the B3LYP/Def2-TZVP level of theory in order to optimize the Chl-a and Chl-c molecules in gas phase. The ZINDO/S and TD-LC-DFT calculations were performed using the ORCA package whereas the TD-LC-DFTB calculations have been performed using the DFTB+ package . In total, 10 excited states have been calculated from which the Q y excitation energies had to be extracted. For the multireference method, we have employed the DFT/MRCI formalism employing an interface to the ORCA package .