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arXiv · 0909.0364

Becke-Johnson-type exchange potential for two-dimensional systems

S. Pittalis·E. Rasanen·C. R. Proetto
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Abstract

We extend the Becke-Johnson approximation [J. Chem. Phys. 124, 221101 (2006)] of the exchange potential to two dimensions. We prove and demonstrate that a direct extension of the underlying formalism may lead to divergent behavior of the potential. We derive a cure to the approach by enforcing the gauge invariance and correct asymptotic behavior of the exchange potential. The procedure leads to an approximation which is shown, in various quasi-two-dimensional test systems, to be very accurate in comparison with the exact exchange potential, and thus a considerable improvement over the commonly applied local-density approximation.

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S. Pittalis, E. Rasanen, C. R. Proetto. 2009-09-25. Becke-Johnson-type exchange potential for two-dimensional systems. https://doi.org/10.1103/physrevb.81.115108

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