First-principles modeling of binary chalcogenides: Recent accomplishments and new achievements

Abstract

This contribution is focussed on a set of first-principles molecular  dynamics results obtained over the past fifteen years for disordered chalcogenides. In the first part, we sketch and review the historical premises underlying research efforts devoted to the understanding of structural properties in liquid and glassy GexSe1−x systems.We stress the importance of selecting well performing exchangecorrelation functionals (within density functional theory) to achieve a correct description of short and intermediate range order. In the second part, we provide a specific, comparative example of structural analysis for chalcogenide GeX4 systems differing by the chemical identity of the X atom. We are able to demonstrate that the correct account of differences between the coordination environments of the two corresponding glasses requires system sizes substantially larger than ∼100 atoms.