The method to reproduce optical spectra by statistical treatment of quantum-mechanical calculations of energy states and photophysical properties in molecular conformers obtained during molecular-dynamical simulation was developed. Polycyclic organic molecules in solvents under thermo-dynamical conditions were considered. This technique was employed to build the first absorption band of estradiol, benzene, and anthracene. Increasing of the spectral intensity in benzene under temperature growth was demonstrated for the lowest excited state. Anthracene emission spectrum was built as well.