Study of a Dielectric Constant Due to Electronic Polarization Using a Semiempirical Molecular Orbital Method I

We studied a method for estimating a dielectric constant due to electronic polarization ε (e) using a semiempirical molecular orbital method. Using Clausius–Mosotti's relation, ε (e) values of 350 organic compounds were calculated using electronic polarizability which was calculated using the modified neglect of diatomic overlap (MNDO) method and experimental density. The calculated dielectric constants ε (e) calc were compared with experimental data ε exp, which were equal to the square of the refractive index, and we found a linear relationship represented by ε exp=0.92 ε (e) calc+0.14. We estimated the dielectric constant using the above relationship for several polymer materials and found a close agreement with the experimental data. It is concluded that this relationship is useful in estimating the experimental dielectric constant due to electronic polarization.