Ab initio study on the variation of stacking interactions of aniline and hydrated aniline systems

The use of appropriate level of theories for studying weak interactions such as 8-8 stacking interactions of aromatic molecules has been an important aspect, since the high level methods have limitations for application to large molecules. The differences in the stacking energies of various aromatic molecular structures are found significant. It is also very important for identifying the most favored stacked models of aniline and hydrated aniline molecules. The effect of basis set in the stacking energies of MP2 calculations is small. The values for HF and MP2 level of theories calculate less electron correlation energy whereas CCSD (T) methods may be used for the calculation of better electron correlation energy. The moderately accurate calculations, MP2 level of theories were found feasible for most of the simple aromatic systems such as benzene, pyridine, aniline etc. In our studies, it has been investigated to study the different 8-8 stacking interaction energies and the effect of change in conformations for aniline and hydrated aniline systems.