Assessment of density functionals for van der Waals complexes of sodium and benzene

Abstract

We present a detailed assessment of state-of-the-art exchange-correlation functionals. The assessment is carried out by comparing potential energy curves of van der Waals complexes of sodium and benzene calculated with density functional theory to extrapolated CCSD(T)/aug-cc-pVQZ values. According to the presented results, the Perdew-Burke-Ernzerhof functional (PBE) displays the best performance among the tested density functionals. PBE is the most accurate functional for the complexes studied, both in terms of absolute and relative accuracy.

Keywords:

• sodium
• benzene
• graphite
• diffusion
• DFT
• assessment
• coupled cluster

Acknowledgements

The present work was carried out in the project Durable Materials in Primary Aluminium Production (DuraMat), financed by the Research Council of Norway, Hydro Primary Metal Technology, Sør-Norge Aluminium (Søral), and Elkem Carbon. Permission to publish the results is gratefully acknowledged. We thank NOTUR for allocation of computational resources and for excellent user support.

Notes

^a This average is based on five complexes.

^b This value is from one complex.

^c This average is based on four complexes.