Relationship between the Critical Points Found by the Electron Localization Function and Atoms in Molecules Approaches in Adducts with Hydrogen Bonds

Abstract

In this work, 11 adducts with hydrogen bonds were studied by using the B3LYP exchange-correlation functional of the Kohn-Sham approach and the Møller-Plesset second-order perturbation theory MP2. With both approaches, the geometry of each adduct was optimized with the aug-cc-pVTZ basis set. The binding energies of the considered systems, found by the MP2 method, range from 1.2 to 8.3 kcal/mol. By using the atoms in molecules (AIM) analysis and the electron localization function (ELF) we found that the critical points positions characteristic of hydrogen bonds obtained by AIM and ELF are very similar each other. Besides, we found a linear correlation between the critical points positions found by AIM and those obtained by ELF with the B3LYP method and also with the MP2 method. The slope of such a linear relationship was close to 1 and the y-intercept close to 0.