Density gradients for the exchange energy of electrons in two dimensions
Abstract
We derive a generalized gradient approximation to the exchange energy to be used in density functional theory calculations of two-dimensional systems. This class of approximations has a long and successful history, but it has not yet been fully investigated for electrons in two dimensions. We follow the approach originally proposed by Becke for three-dimensional systems [Int. J. Quantum Chem. 23, 1915 (1983), J. Chem. Phys. 85, 7184 (1986)]. The resulting functional depends on two parameters that are adjusted to a test set of parabolically confined quantum dots. Our exchange functional is then tested on a variety of systems with promising results, reducing the error in the exchange energy by a factor of 4 with respect to the simple local density approximation.
Keywords
Cite
@article{arxiv.0810.4869,
title = {Density gradients for the exchange energy of electrons in two dimensions},
author = {S. Pittalis and E. Rasanen and J. G. Vilhena and M. A. L. Marques},
journal= {arXiv preprint arXiv:0810.4869},
year = {2009}
}