Fig. 5. Theoretical interpretation of photoluminescence of the molecular fluorophore. (a) Experimental and (b) TD-DFT CAM-B3LYP computed absorption and emission spectra along with the vibronic overtones. (c) Natural transition orbitals (NTOs) and canonical molecular orbitals (HOMO and LUMO) of the organic fluorophore, QXPDA, responsible for the red component.
