The quantum mechanical calculations have been utilized using the density function theory (DFT) by B3LYP method on the basis set 6-31g(d,p) to calculate the single point energy of Polyaniline emeraldine nitrate salt (PANI-nitrate). Polyaniline emeraldine sulphate (PANI-Sulphate) was also calculated on the same level. At the end the PANI-nitrate@Ag core-shell was calculated on the same level of calculations. For the previously named structures, the total dipole moment vector of every molecule was also calculated in addition to the energy band gap between the highest occupied molecular orbital (HOMO) and the lowest occupied molecular orbital (LUMO) and the distribution of the Electrostatic potential. More investigations for the studied molecules have been done in the presence of water molecules.