Caracterização de ligações químicas via Teoria do Funcional da Densidade: uma proposta para auxiliar o ensino

Abstract

With the computers advancement, in the sixties, new scientific theories have appeared that caused a true revolution in order to solve microscopic problems in complex systems, making it possible the research, increasingly, of material intrinsic quantum properties. The Density Functional Theory, whose acronym, in english, is DFT ( Density Functional Theory), came to facilitate the study of nanomaterials electronics structures, using the functional of electronics densities as parameter for getting the observable of a quantum systems. This work it’s main aim use DFT’s calculations for simulating three-dimensional surfaces of electronics densities in binary compounds, characterizing therefore the different types of chemical bonding, making your study more attractive, facilitating your teaching-learning and allowing that students have understood the macroscopic characteristics of the material. Initially, we will bring forward the theories taught currently in the classroom to explain each type of chemical bonding. Then, there will be a resumed approach of relevant concepts of the Density Functional Theory, your history, which has benefited, what needs to be improved and perspectives. With that, we will do a few computer simulations using the software package Gaussian 09 for making DFT’s calculations and, as graphic interface, the Avogrado program, where will happen the modeling molecules and of the electronics surfaces. Addition to probability electronic calculations, we will to measure other variables as the connections lengths and the analysis of the partial loads of Mülliken of every atom, so that we can do analogies with the properties already known of the test material. Finally, we will discuss how to apply them in classroom, in secondary school as well as in higher education, by basing itself upon on the PCN’s (National Curricular Parameters) and in the LDB ( Law of Directives and Bases), proposing a innovative model of class as an auxiliary tool in the teaching, where the students might learn differentiate the chemical bonding more easily, visualizing the electronics areas of the compounds.