Analysis of the basis set and correlation effects on the computation of molecular polarizabilities using molecular polarization maps

In the present report, we analyze the effect of augmenting the basis set and the level of the theory in the computation of the molecular polarization potential and it is used as a tool to understand their spatial effects in the calculation of molecular polarizabilities. This is analyzed in the present report through the results obtained for three reference molecules: hydrogen cyanide, formaldehyde and urea. Accordingly, different basis sets were used for the calculations, including: 6-31G(D), 6-31G(D,P), 6-31G(2D,2P) and 6-31++G(2D,2P). On the other hand, calculations at different levels of the theory were considered, including: Hartree–Fock, Moller–Plesset second order (MP2) and fourth order (MP4) as well as the functionals BLYP and B3LYP at the density functional theory. The results of the polarization maps reveal similar trends observed with the calculation of the different components of the polarizability tensor. However, the use of the maps permits to understand spatial effects specific for each level of calculation and each basis set.