Regensburg 2013 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 3: Computational Materials Modelling - Fundamentals

MM 3.3: Vortrag

Montag, 11. März 2013, 10:45–11:00, H24

How van der Waals Interactions Influence Cohesive Properties of Solids — •Guo-Xu Zhang, Anthony M. Reilly, Alexandre Tkatchenko, and Matthias Scheffler — Fritz-Haber-Institut der MPG, Faradayweg 4-6, 14195 Berlin, Germany

Standard semilocal and hybrid density functionals are widely used for studying cohesive properties of many covalent, metallic, and ionic materials. Only recently it has been recognized that long-range van der Waals (vdW) interactions, that are missing in all semilocal and hybrid functionals, are important for an accurate description of cohesion in solids. Here we construct a database of 64 solids where reference cohesive properties are obtained from a critical revision of the available experimental data. All-electron DFT calculations with explicit treatment of zero-point vibrations for all cohesive properties are carried out using the local-density approximation (LDA), Perdew-Burke-Ernzerhof (PBE) GGA, and the empirical meta-GGA M06-L [1] functionals. For 23 semiconductor solids, we also carry out PBE and M06-L calculations with the inclusion of fully screened long-range vdW energy [2]. We find that PBE is the most systematic from the three employed functionals, and its accuracy is improved by a factor of two after the inclusion of vdW interactions. The LDA functional considerably overbinds for all the studied solids. The M06-L functional describes middle-range correlation better for certain semiconductors and ionic crystals, but fails for heavier semiconductors and metals. [1] Zhao and Truhlar, JCP (2006). [2] Tkatchenko, DiStasio, Car, Scheffler, PRL (2012).