Theoretical studies have been carried out on bio active molecules such as Naphthalene (npa) and its derivatives naphthalene-2-sulfonic acid (nsa) 1-nitroso-2-naphthol (nnol) using both Ab initio HF DFT-B3LYP methods with 6-311++G(d,2p) basis sets. The geometrical parameters, molecular properties vibrational spectra of nsa, nnol npa were calculated analyzed. Geometrical optimizations the done by...