Polyaniline (PANT) is a very important polymer owing to its diversified chemistry and interesting physical properties. To investigate the structural parameters of polyaniline pernigraniline base (PANT PNB), DFT geometry optimization using B3LYP/6-31G** basis set was carried out on its two well-known model compounds. Electrostatic potential surfaces have been mapped over the electron density isosurfaces to obtain information about size, shape, charge distribution, and chemical reactivity of these molecules. The heat capacity of PANT PNB in the temperature range 10-300 K is being reported for the first time.