Source-Free Exchange-Correlation Magnetic Fields in Density Functional Theory

Alternative separation of exchange and correlation in density-functional theory

Introduction to Density Functional Theory and Exchange-Correlation Energy Functionals

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Magnetic exchange couplings from noncollinear spin density functional perturbation theory.

We propose a method for the evaluation of magnetic exchange couplings based on noncollinear spin density functional calculations. The method employs the second derivative of the total Kohn-Sham energy of a single reference state, in contrast to approximations based on Kohn-Sham total energy differences. The advantage of our approach is twofold: It provides a physically motivated picture of the ...

Density-functional approximations for exchange and correlation

Density-functional theory (DFT) is based on two pivotal theorems due to Hohenberg and Kohn [1]. The first theorem states that the ground-state density ρ(r) of a system of electrons uniquely determines the Hamiltonian and hence all properties that can be derived from it. Using mathematical language we can say that the total electronic energy of the system is a functional of the electron density,

Two-dimensional limit of exchange-correlation energy functional approximations in density functional theory

We investigate the behavior of three-dimensional (3D) exchange-correlation energy functional approximations of density functional theory in anisotropic systems with two-dimensional (2D) character. Using two simple models, quasi-2D electron gas and two-electron quantum dot, we show a fundamental limitation of the local density approximation (LDA), and its semi-local extensions, generalized gradi...