QTAIM Densities and Ab Initio Basis Sets: A Chemometrical Analysis of the Intermolecular Electronic Densities of the Hydrogen-Bonded Complexes C2H4O•••HX (X = F, CN, NC, and CCH)

The intermolecular electronic densities of the hydrogen-bonded complexes C2H4O•••HX (X = F, CN, NC, and CCH) were determined by calculations performed at the level of Density Functional Theory (DFT). The B3LYP functional and the Pople’s 6-31G split-valence basis set were combined with (11) valence, (++) diffuse and (d,p) polarization functions with the purpose to determine the optimized geometries of the C2H4O•••HX complexes. Through these geometries, their intermolecular electronic densities p(r,x)QTAIM calculated from Quantum Theory of Atoms in Molecules (QTAIM) were examined through the Hierarchical Cluster Analysis (HCA) and Two-Level Factorial Designs (TLFD) statistical techniques. Although it is well-known that the QTAIM approach was projected with a slight dependence from ab initio basis sets, our results revealed a good relationship between p– (r,x)QTAIM and the values estimated by the chemometric analysis (p(r,x)EST) computed essentially by valence (11) and diffuse (++) functions.