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.

References in corpus (5)

• Full configuration interaction approach to the few-electron problem in artificial atoms
• Testing of two-dimensional local approximations in the current-spin and spin-density-functional theories
• Exchange-energy functionals for finite two-dimensional systems
• Local correlation functional for electrons in two dimensions
• Electron localization function for two-dimensional systems

Cited by in corpus (4)

• Gaussian approximations for the exchange-energy functional of current-carrying states: Applications to two-dimensional systems
• Correlation energy of two-dimensional systems: Toward non-empirical and universal modeling
• Exact Coulomb cutoff technique for supercell calculations in two dimensions
• Orbital-free energy functional for electrons in two dimensions