Beyond RPA correlation energies: Evaluation of model exchange-correlation kernels

ORAL

Abstract

The description of van der Waals dispersion interactions using the so called EXX/RPA method has recently attracted a widespread interest. Overall, equilibrium distances and cohesive energies of weakly bound molecular systems exhibit a significant improvement over the the results of semi-local Density Functional Theory calculations [1,2], due to the proper inclusion of long-range correlation effects. However, cohesive energies still result to be underestimated with respect to experiments in several cases. This is mainly due to the neglect of the exchange-correlation kernel in evaluating response functions entering the correlation energy expression. In this work, we study the effect of several model exchange-correlation kernels and evaluate their performance for molecular systems. \\[4pt] [1] D. Lu, Y. Li, D. Rocca and G. Galli, Phys. Rev. Lett. 102, 206411 (2009)\\[0pt] [2] Y. Li, D. Lu, H-V Nguyen and G. Galli, J. Phys. Chem. A, 114, 1944-1952 (2010) and D. Lu, H-V Nguyen, and G. Galli, J. Chem. Phys. 133, 154110 (2010)

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Authors

  • Deyu Lu

    Brookhaven National Laboratory, Center for Functional Nanomaterials, Brookhaven National Laboratory

  • Giulia Galli

    University of California, Davis, Department of Chemistry and Department of Physics, University of California at Davis, Davis, California, USA, Department of Chemistry \& Department of Physics, Unversity of California, Davis, Department of Chemistry and Department of Physics, UC Davis, UC Davis, University of California-Davis, Department of Chemistry and Department of Physics, University of California, Davis, Univeristy of California, Davis, University of California Davis, Davis, CA95616, University of California, Davis, USA