On the applicability of the molecular dynamics SCC-DFTB treatment on optical spectra simulations for thiophene and phenyl containing oligomers

► Theoretical SCC-DFTB and DFT, MP2 study of neutral 2,2′-bithiophene and 2-phenylthiophene. ► The investigation of the torsional potentials. ► The combination of molecular dynamics geometries with the TD-B3LYP or CIS-ZINDO excitation energies.