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Related papers: Exchange-energy functionals for finite two-dimensi…

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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…

Strongly Correlated Electrons · Physics 2009-01-07 S. Pittalis , E. Rasanen , J. G. Vilhena , M. A. L. Marques

We consider density functionals for exchange and correlation energies in two-dimensional systems. The functionals are constructed by making use of exact constraints for the angular averages of the corresponding exchange and correlation…

Strongly Correlated Electrons · Physics 2010-02-25 E. Rasanen , S. Pittalis

Semi-local density functionals for the exchange-correlation energy of electrons are extensively used as it produce realistic and accurate results for finite and extended systems. The choice of techniques play crucial role in constructing…

Materials Science · Physics 2017-11-01 Subrata Jana , Prasanjit Samal

A recently developed quasi two-dimensional exact-exchange formalism within the framework of Density Functional Theory has been applied to a strongly inhomogeneous interacting electron gas, and the results were compared with state-of-the-art…

Condensed Matter · Physics 2009-11-07 S. Rigamonti , F. A. Reboredo , C. R. Proetto

We construct a generalized-gradient approximation for the exchange-energy density of finite two-dimensional systems. Guided by non-empirical principles, we include the proper small-gradient limit and the proper tail for the exchange-hole…

Strongly Correlated Electrons · Physics 2014-03-26 J. G. Vilhena , E. Rasanen , M. A. L. Marques , S. Pittalis

We present a practical and accurate density functional for the exchange-correlation energy of electrons in two dimensions. The exchange part is based on a recent two-dimensional generalized-gradient approximation derived by considering the…

Strongly Correlated Electrons · Physics 2010-06-30 E. Rasanen , S. Pittalis , J. G. Vilhena , M. A. L. Marques

The capability of density-functional theory to deal with the ground-state of strongly correlated low-dimensional systems, such as semiconductor quantum dots, depends on the accuracy of functionals developed for the exchange and correlation…

Strongly Correlated Electrons · Physics 2009-02-25 S. Pittalis , E. Rasanen , C. Proetto , E. K. U. Gross

A simple exact-exchange density-functional method for a quasi-two-dimensional electron gas with variable density is presented. An analytical expression for the exact-exchange potential with only one occupied subband is provided, without…

Condensed Matter · Physics 2009-11-07 F. A. Reboredo , C. R. Proetto

Most density functionals have been developed by imposing the known exact constraints on the exchange-correlation energy, or by a fit to a set of properties of selected systems, or by both. However, accurate modeling of the conventional…

Materials Science · Physics 2016-08-24 Jianmin Tao , Yuxiang Mo

Commonly used semilocal density functional approximations for the exchange-correlation energy fail badly when the true two dimensional limit is approached. We show, using a quasi-two-dimensional uniform electron gas in the infinite barrier…

Materials Science · Physics 2015-05-13 Lucian A. Constantin

Electronic structure calculations are routinely carried out within the framework of density-functional theory, often with great success. For electrons in reduced dimensions, however, there is still a need for better approximations to the…

Strongly Correlated Electrons · Physics 2009-09-22 S. Pittalis , E. Rasanen , E. K. U. Gross

We test local and semi-local density functionals for the electronic exchange for a variety of systems including atoms, molecules, and atomic chains. In particular, we focus on a recent universal extension of the Becke-Johnson exchange…

Materials Science · Physics 2010-11-01 Micael J. T. Oliveira , Esa Räsänen , Stefano Pittalis , Miguel A. L. Marques

The construction of meta generalized gradient approximations based on the density matrix expansion (DME) is considered as one of the most accurate technique to design semilocal exchange energy functionals in two-dimensional density…

Materials Science · Physics 2018-05-09 Abhilash Patra , Subrata Jana , Prasanjit Samal

We present an approach based on density-functional theory for the calculation of fundamental gaps of both finite and periodic two-dimensional (2D) electronic systems. The computational cost of our approach is comparable to that of total…

Materials Science · Physics 2021-08-11 Alberto Guandalini , Alice Ruini , Esa Räsänen , Carlo Andrea Rozzi , Stefano Pittalis

In order to assess the accuracy of commonly used approximate exchange-correlation density functionals, we present a comparison of accurate exchange and correlation potentials, exchange energy densities and energy components with the…

Condensed Matter · Physics 2007-05-23 Claudia Filippi , Xavier Gonze , C. J. Umrigar

The Coulomb exchange and correlation energy density functionals for electron systems are applied to nuclear systems. It is found that the exchange functionals in the generalized gradient approximation provide agreements with the exact-Fock…

Nuclear Theory · Physics 2019-12-09 Tomoya Naito , Ryosuke Akashi , Gianluca Colò , Haozhao Liang , Xavier Roca-Maza

We derive an approximate local density functional for the exchange-correlation energy to be used in density-functional calculations of two-dimensional systems. In the derivation we employ the Colle-Salvetti wave function within the scheme…

Strongly Correlated Electrons · Physics 2010-07-12 S. Sakiroglu , E. Rasanen

Most approximate exchange-correlation functionals used within density functional theory are constructed as the sum of two distinct contributions for exchange and correlation. Separating the exchange component from the entire functional is…

Condensed Matter · Physics 2009-10-28 Claudia Filippi , C. J. Umrigar , Xavier Gonze

Quantum rings can be characterized by a specific radius and ring width. For this rich class of physical systems, an accurate approximation for the exchange-hole potential and thus for the exchange energy is derived from first principles.…

Strongly Correlated Electrons · Physics 2009-02-04 E. Rasanen , S. Pittalis , C. R. Proetto , E. K. U. Gross

We study the properties of the lower bound on the exchange-correlation energy in two dimensions. First we review the derivation of the bound and show how it can be written in a simple density-functional form. This form allows an explicit…

Strongly Correlated Electrons · Physics 2010-02-25 E. Rasanen , S. Pittalis , C. R. Proetto , K. Capelle
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