English
Related papers

Related papers: Exact-exchange relativistic density functional the…

200 papers

A new method for extracting ensemble Kohn-Sham potentials from accurate excited state densities is applied to a variety of two electron systems, exploring the behavior of exact ensemble density functional theory. The issue of separating the…

Ensemble density functional theory (eDFT) is an exact time-independent alternative to time-dependent DFT (TD-DFT) for the calculation of excitation energies. Despite its formal simplicity and advantages in contrast to TD-DFT (multiple…

Strongly Correlated Electrons · Physics 2017-01-19 Killian Deur , Laurent Mazouin , Emmanuel Fromager

This work presents an alternative, general, and in-principle exact extension of electronic Kohn-Sham density functional theory (KS-DFT) to the fully quantum-mechanical molecular problem. Unlike in existing multi-component or…

Chemical Physics · Physics 2024-05-14 Emmanuel Fromager , Benjamin Lasorne

Improving the predictive capability of molecular properties in ab initio simulations is essential for advanced material discovery. Despite recent progress making use of machine learning, utilizing deep neural networks to improve quantum…

Chemical Physics · Physics 2021-09-22 Muhammad F. Kasim , Sam M. Vinko

We introduced a new electron density n({\epsilon}) by projecting the spatial electron density n(r) onto the energy coordinate {\epsilon} defined with the external potential \upsion (r) of interest. Then, a density functional theory (DFT)…

Chemical Physics · Physics 2018-02-20 Hideaki Takahashi

Reduced density-matrix functional theory (RDMFT) is a promising alternative approach to the problem of electron correlation. Like standard density functional theory, it contains an unknown exchange-correlation functional, for which several…

Chemical Physics · Physics 2017-03-03 N. N. Lathiotakis , Miguel A. L. Marques

The exchange-correlation potential experienced by an electron in the free space adjacent to a solid surface or to a low-dimensional system defines the fundamental image states and is generally important in surface- and nano-science. Here we…

Mesoscale and Nanoscale Physics · Physics 2016-06-01 V. U. Nazarov

Orbital-free Density Functional Theory (OF-DFT) has been used when studying atoms, molecules and solids. In nuclear physics, there has been basically no application of OF-DFT so far, as the Density Functional Theory (DFT) has been widely…

Nuclear Theory · Physics 2023-08-03 Gianluca Colo' , Kouichi Hagino

The exchange-correlation energy in Kohn-Sham density functional theory is expressed as a functional of the electronic density and the Kohn-Sham orbitals. An alternative to Kohn-Sham theory is to express the energy as a functional of the…

Computational Physics · Physics 2009-10-31 S. Goedecker , C. Umrigar

Modern density functional theory (DFT) calculations employ the Kohn-Sham (KS) system of non-interacting electrons as a reference, with all complications buried in the exchange-correlation energy (Exc). The adiabatic connection formula gives…

Other Condensed Matter · Physics 2009-10-02 Zhenfei Liu , Kieron Burke

Following a recent work [Gal, Phys. Rev. A 64, 062503 (2001)], a simple derivation of the density-functional correction of the Hartree-Fock equations, the Hartree-Fock-Kohn-Sham equations, is presented, completing an integrated view of…

Chemical Physics · Physics 2008-09-11 Tamas Gal

The accurate description of open-shell molecules, in particular of transition metal complexes and clusters, is still an important challenge for quantum chemistry. While density-functional theory (DFT) is widely applied in this area, the…

Chemical Physics · Physics 2012-10-26 Christoph R. Jacob , Markus Reiher

By exploiting freedoms in the definitions of 'correlation', 'exchange' and 'Hartree' physics in ensemble systems we better generalise the notion of 'exact exchange' (EXX) to systems with fractional occupations functions of the frontier…

Atomic Physics · Physics 2014-07-28 Tim Gould , John F. Dobson

The derivative discontinuity of the exchange-correlation (xc) energy at integer particle number is a property of the exact, unknown xc functional of density functional theory (DFT) which is absent in many popular local and semilocal…

Strongly Correlated Electrons · Physics 2015-06-11 Gao Xianlong , A-Hai Chen , I. V. Tokatly , S. Kurth

Capturing the discontinuous shift by $\Delta$ in the exact exchange-correlation (xc) potential is the standard proposal for calculating the fundamental gap, $E_\mathrm{g}$, from the Kohn-Sham (KS) gap, $\varepsilon_\mathrm{g}$, within KS…

Materials Science · Physics 2021-01-14 M. J. P. Hodgson , J. Wetherell , Emmanuel Fromager

Relativistic energy density functionals (REDF) provide a complete and accurate, global description of nuclear structure phenomena. A modern semi-empirical functional, adjusted to the nuclear matter equation of state and to empirical masses…

Nuclear Theory · Physics 2015-06-05 V. Prassa , T. Niksic , G. A. Lalazissis , D. Vretenar

Guiding by the relativistic local density approximation, we explore a phenomenological formula for the coupling strength of Coulomb field to take into account the Coulomb exchange term effectively in the relativistic Hartree approximation.…

Nuclear Theory · Physics 2013-05-27 Z. M. Niu , Q. Liu , Y. F. Niu , W. H. Long , J. Y. Guo

The conventional approaches to the inverse density functional theory problem typically assume non-degeneracy of the Kohn-Sham (KS) eigenvalues, greatly hindering their use in open-shell systems. We present a generalization of the inverse…

Chemical Physics · Physics 2024-01-09 Bikash Kanungo , Jeffrey Hatch , Paul M. Zimmerman , Vikram Gavini

By inverting the time-dependent Kohn-Sham equation for a numerically exact dynamics of the helium atom, we show that the dynamical step and peak features of the exact correlation potential found previously in one-dimensional models persist…

Chemical Physics · Physics 2022-07-28 Davood Dar , Lionel Lacombe , Johannes Feist , Neepa Maitra

The reconstruction of the exchange-correlation potential from accurate ab initio electron densities can provide insights into the limitations of the currently available approximate functionals and provide guidance for devising improved…

Strongly Correlated Electrons · Physics 2013-02-05 Katharina Boguslawski , Christoph R. Jacob , Markus Reiher