You should correlate the 0-0 transitions. The situation with oscillator strengths is more complicated - they are usually difficult to be experimentally obtained. Perhaps the attached paper can help. See also the recent paper of Carlo Adamo in PCCP (http://pubs.rsc.org/en/content/articlelanding/2014/cp/c3cp55336a)

Thank You Sir

Mr. Karmakar,

Your experimental spectrum is A (or intensity) = f (lambda [nm]).

The theoretical computations yield energies of the electronic transitions in eV and nm and thus the theoretical lambda max as physical meaning corresponds to the experimental lambda max. There is not any additional computations, than those ones associated with the scaling depending on the errors of the different theoretical levels.

Towards A: According to BLB law you have A = e.b.c and e = A/(b.c), meaning that "e" (extinction coef) expresses probability of an electronic transition from the ground S0 state to corresponding excited singlet state/s. This value you have determined experimentally. Theoretically, however you have f - oscillator strengths, which exactly express the same transition probabilities, meaning that it contains information about intensity of an absorption band or it contains information about "A" in your experimental spectrum. Because of both f and "e" are joined in an equation shown as attachment. As you can see a direct relationship between f and e, where you have only a multiplication to a constant containing m,c,pi,NL, and n. All the last quantities are known constants, however, excluding n, which is refractive index of the medium. It often is taken as n ca. 1 for analysis of water, for example, and other polar protic solvents used within the frame of strongly diluted solutions, due to the fact that within the frame of UV-VIS measurements we have operated with strongly diluted solutions.

In this context the lambdasmaxs between theory and experiment are compared directly, while for intensities, resp., f you should take into consideration this shifting at a const. + the error of theoretical approaches expressed by the scaling factor, which is valid towards the f as well. If you would like to obtain the "e" from your theoretical f-data you can use the shown example (attachment), which illustrates how to convert f into e and vise versa.

NB! The stated above comments are towards absorption spectra in solution!

You can pay attention to a discussion as well as relating sub discussions and attachments to them, showing corresponding transformations of the Lmax and various presentation of theoretical electronic absorption spectra:

https://www.researchgate.net/post/How_do_I_calculate_adsorption_energy_from_molecular_dynamics_simulations

Thank You Dr. Ivanova for your valuable answer.