Rafael B. de Almeida

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In this work we have analyzed the bond character of a series of representative diatomic molecules, using valence bond and the atoms in molecules points of view. This is done using generalized valence-bond calculations. We have also employed more exigent levels, as configuration interaction with single and double excitations and complete active space(More)
In this paper we study the manifestations of cooperative effects in the formation of clusters4-methyloxycarbonyl-2-azetidinone. Structural properties of the clusters were obtained at the DFT/B3LYP/6-311G(d) level of calculation, while the energetic ones were calculated at the B3LYP/6-311G(d), B3LYP/6-31++G(d,p) and HCTH407/6-31++G(d,p) DFT levels. The(More)
In this work we have explored the performance of two functions, recently proposed by Ayers [J. Chem. Sci., 2005, 117, 441], with the purpose of quantifying local electron localization. The first function, ζ(h), measures the total fluctuation per electron in the number of electrons at a given position r(1), while the second one, ζ(R), is a local(More)
Recently, multi component crystals composed of two or more molecules that form a unique crystalline structure having unique phase and properties, where its components are bond together via hydrogen bonds, have been the subject of great deal of attention, in particular those where aminoacids participate in their structure. In this work we have studied a(More)
The study of magnetic phenomena in nanometer scale is essential for development of new technologies and materials. It also leads to a better understanding of magnetic properties of matter. An approach to the study of magnetic phenomena is the use of a physical model and its computational simulation. For this purpose, in previous works we have developed a(More)
In this work, we have explored the validity of the hypotheses on which rest the Hammett's approach to quantify the substituent effect on a reaction center, by applying two DFT energy decomposition schemes. This is performed by studying the change in the total electronic energy, ΔΔE, associated with a proton transfer isodesmic equilibrium. For this reaction,(More)