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Related papers: Exchange and correlation energy functionals for tw…

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We consider electronic exchange and correlation effects in density-functional calculations of two-dimensional systems. Starting from wave function calculations of total energies and electron densities of inhomogeneous model systems, we…

Mesoscale and Nanoscale Physics · Physics 2012-05-30 Ilja Makkonen , Mikko M. Ervasti , Ville Kauppila , Ari Harju

Implicit and explicit density functionals for the exchange energy in finite two-dimensional systems are developed following the approach of Becke and Roussel [Phys. Rev. A 39, 3761 (1989)]. Excellent agreement for the exchange-hole…

Strongly Correlated Electrons · Physics 2008-05-08 S. Pittalis , E. Rasanen , N. Helbig , E. K. U. Gross

We propose a simple analytic representation of the correlation energy for the two-dimensional electron gas, as a function of the density and the spin polarization. This new parametrization includes most of the known high- and low- density…

Strongly Correlated Electrons · Physics 2007-05-23 Paola Gori-Giorgi , Claudio Attaccalite , Saverio Moroni , Giovanni B. Bachelet

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

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

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 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

We have obtained an analytic expression for the ring diagrams contribution to the correlation energy of a two dimensional electron liquid as a function of the uniform fractional spin polarization. Our results can be used to improve on the…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 S. Chesi , G. F. Giuliani

We derive a local approximation for the correlation energy in two-dimensional electronic systems. In the derivation we follow the scheme originally developed by Colle and Salvetti for three dimensions, and consider a Gaussian approximation…

Strongly Correlated Electrons · Physics 2008-11-21 S. Pittalis , E. Rasanen , M. Marques

Based on exact limits and quantum Monte Carlo simulations, we obtain, at any density and spin polarization, an accurate estimate for the energy of a modified homogeneous electron gas where electrons repel each other only with a long-range…

Materials Science · Physics 2009-11-11 Simone Paziani , Saverio Moroni , Paola Gori-Giorgi , Giovanni B. Bachelet

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

The description of interacting many-electron systems in external magnetic fields is considered in the framework of the optimized effective potential method extended to current-spin-density functional theory. As a case study, a…

Materials Science · Physics 2011-01-14 N. Helbig , S. Kurth , S. Pittalis , E. Räsänen , E. K. U. Gross

The ground state energy of the two--dimensional uniform electron gas has been calculated with fixed--node diffusion Monte Carlo, including backflow correlations, for a wide range of electron densities as a function of spin polarization. We…

Strongly Correlated Electrons · Physics 2009-11-07 Claudio Attaccalite , Saverio Moroni , Paola Gori-Giorgi , Giovanni B. Bachelet

Accurate treatment of the electronic correlation in inhomogeneous electronic systems, combined with the ability to capture the correlation energy of the homogeneous electron gas, allows to reach high predictive power in the application of…

Strongly Correlated Electrons · Physics 2010-06-22 E. Rasanen , S. Pittalis , C. R. Proetto

A functional $E_{xc}[\rho(\r,\epsilon)]$ is presented, in which the exchange and correlation energy of an electron gas depends on the local density of occupied states. A simple local parametrization scheme is proposed, entirely from first…

Materials Science · Physics 2009-11-10 Jose M. Soler

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

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

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

A widely used approximation to the exchange-correlation functional in density functional theory is the local density approximation (LDA), typically derived from the properties of the homogeneous electron gas (HEG). We previously introduced…

Other Condensed Matter · Physics 2018-06-27 Mike Entwistle , Michele Casula , Rex Godby

The construction of density-functional approximations is explored by modeling the adiabatic connection em locally, using energy densities defined in terms of the electrostatic potential of the exchange-correlation hole. These local models…

Chemical Physics · Physics 2016-05-04 Stefan Vuckovic , Tom Irons , Andreas Savin , Andrew M. Teale , Paola Gori-Giorgi
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