Achieving predicting power for the calculated properties of disordered materials: the role of exchange-correlation functionals within DFT

by Prof. Carlo Massobrio (Institut de Physique et Chimie des Matériaux de Strasbourg, France)

Tuesday 28 Oct 2014, 15:00 → 16:00 Europe/Rome

Sala Touschek (Dipartimento di Fisica - Ed. G. Marconi)

Disordered network-forming materials have proved a valuable playground for testing and improving the performances of current atomic-scale recipes aimed at a quantitative modeling of materials properties. For the specific family of chalcogenides (GexSe(1-x), we have described the structural changes undergone by this family of disordered network-forming materials by resorting to first-principles molecular dynamics within density functional theory. Liquid and glassy systems have been considered by taking suitable statistical averages over extended time trajectories. Special attention has been payed to the role of the exchange-correlation functionals within DFT, due to the delicate interplay of ionic and covalent bonding inherent in the Ge-Se interaction. We show that functional featuring enhanced electron localization properties are the best suited to achieve a successful comparison with measured structural properties, both in real and in reciprocal space.