ESTUDO DAS LIGACOES DE HIDROGENIO PARA DIMEROS FORMADOS PELAS MOLECULAS DE H_2O, NH_3, HF, HCl E HBr ATRAVES DE CALCULOS BASEADOS EM PRIMEIROS PRINCIPIOS

摘要

Hydrogen bond energies of fifteen dimers were calculated using the large basis set 6-311++G(3df,3pd), at Hartree-Fock (HF) level including Moller-Plesset (MP2) calculations. The procedure for obtaining such energies were based on the dimer's energy rise provoked by increasing in intermolecular distance of the system component units. Deviations from a strictly linear hydrogen bond were investigated and rotational barriers were also computed allowing the calculation of the second order attractive interactions. In order to provide a more objective definition of hydrogen bond, a lower energy limit was proposed in place of the merely empirical parameters employed in the classical definition.