Session L36 - General Poster Session II.
POSTER session, Wednesday morning, March 22
Exhibit Hall, MCC
In the Density Functional Formalism, the ground state energy of any electron system is given by an unique universal functional of the density. As a consequence, the same functional must be able to describe systems confined in any number of spatial dimensions. Concretely, the expression of the functional for a 2D system should result from the 3D one applied to a system where the density profile is a delta function along one of the coordinates. In this work, we present a study on the ability of several models for the exchange-correlation (XC) energy to verify this property. We obtain the behavior of various well known approximations in the strict 2D limit. We show that the LDA and GGA approximations diverge. However, the weighted density approximation (WDA) gives an accurate XC energy for the 2D electron gas as well as a good description of its pair correlation function. The above theoretical study is illustrated by applying these models to more realistic quasi-2D electron systems.