I am performing some TD-DFT calculations to reproduce the UV-Vis spectrum of a molecule using Gaussian. After optimizing the structure, I performed a TD-DFT calculation with 150 states and I tried different basis sets and functionals (such as B3LYP, CAMB3LYP, M062X).
However, in all cases, I fail to reproduce the spectra (in terms of numbers of peaks, not only the position) and it seems very far from the experiments.
I wouldn't expect the solvent to change the resolution of the peaks. Does anyone have some tips on how to enhance these types of calculations?