First-principle vs experimental design of nanomaterials: Fid-Bau Portal

First-principle vs experimental design of nanomaterials

Mounkachi, Omar / Benyoussef, Abdelilah / Hamedoun, Mohamed

Inhaltsverzeichnis

"The first-principle approach is designed for the interpretation of the experimental observations and prediction of properties for new nanomaterials. The understanding of physical phenomena requires a description at the atomic scale where size and geometric organization play important roles. The major challenge is to model systems as close as possible to those developed in the laboratory. The complexity both in terms of the geometric structure and chemical composition that comprise the modeling of such systems requires an entire panel of approaches ranging from semi-empirical methods to ab initio methods. At the atomic scale, the elementary bricks of the buildings are atoms. The cohesion and dynamics of these buildings are the result of interactions between these atoms. Two major classes of modeling techniques for these buildings can be distinguished: Electronic structure calculations and molecular simulation methods. Molecular simulation methods are limited in their application since they cannot be used to model properties that depend on the electronic structure. As part of the electronic structure calculations, the building is described by the notion of wave function. One of the fundamental tasks of quantum physics is to solve a differential equation according to the electronic, nuclear and spin coordinates via the Schrödinger equation. The resolution of this equation in analytical form is impossible, except in the case of hydrogenites. Different numerical resolution methods have been developed based on a series of simplifications and successive approximation techniques. Once solved, this equation gives the total energy of the system, the associated wave function, and the energies of the electronic states"--