DFT and MP2 calculations on new series of hydroxythioxanthones

► Molecular structure and geometrical parameters of hydroxythioxanthones are obtained from DFT and MP2 calculation. A close agreement has been observed between the experimental and theoretical data. ► Based on MP2 calculations some of hydroxythioxanthones have a butterfly structure. ► The spectral data such as IR, NMR and UV calculated and compared with experimental data. ► The HOMO and LUMO energies have been calculated. ► Natural bond orbital (NBO) study explains charge delocalization of the molecules.