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Related papers: Degenerate Density Perturbation Theory

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The self consistent version of the density functional theory is presented, which allows to calculate the ground state and dynamic properties of finite multi-electron systems. An exact functional equation for the effective interaction, from…

Materials Science · Physics 2017-08-23 M. Ya. Amusia , A. Z. Msezane , V. R. Shaginyan

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

We extend the density functional perturbation theory formalism to the case of non-collinear magnetism. The main problem comes with the exchange-correlation (XC) potential derivatives, which are the only ones that are affected by the…

Computational Physics · Physics 2019-05-15 Fabio Ricci , Sergei Prokhorenko , Marc Torrent , Matthieu J. Verstraete , Eric Bousquet

Special bases of orthogonal polynomials are defined, that are suited to expansions of density and potential perturbations under strict particle number conservation. Particle-hole expansions of the density response to an arbitrary…

Nuclear Theory · Physics 2009-11-11 B. G. Giraud , A. Weiguny , L. Wilets

Approximate functionals used in practical density functional theory (DFT) deviate from the piecewise linear behavior of the exact functional for fractional charges. This deviation causes excess charge delocalization, which leads to…

Chemical Physics · Physics 2018-10-23 Diptarka Hait , Martin Head-Gordon

We study static correlation and delocalisation errors and show that even methods with good energies can yield significant delocalization errors that affect the density, leading to large errors in predicting {\em e.g.} dipole moments. We…

Chemical Physics · Physics 2020-06-01 Maria Hellgren , Tim Gould

Aspects of Density Functional Resonance Theory (DFRT) [Phys. Rev. Lett. \textbf{107}, 163002 (2011)], a recently developed complex-scaled version of ground-state Density Functional Theory (DFT), are studied in detail. The asymptotic…

Quantum Physics · Physics 2015-06-04 Daniel L. Whitenack , Adam Wasserman

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

We develop an ensemble density functional theory for the fractional quantum Hall effect using a local density approximation. Model calculations for edge reconstructions of a spin-polarized quantum dot give results in good agreement with…

Condensed Matter · Physics 2009-10-28 O. Heinonen , M. I. Lubin , M. D. Johnson

Exchange-correlation potentials vxc and energy densities exc are derived for integer and fractional electron counts using an orbital-averaged Kohn-Sham inversion procedure. The reference densities for inversion come from full configuration…

Chemical Physics · Physics 2025-04-30 Vaibhav Khanna , Bikash Kanungo , Jeffrey Hatch , Joshua Kammeraad , Paul M. Zimmerman

A fundamental weakness of density functional theory (DFT) is the difficulty in making systematic improvements to approximations for the exchange and correlation functionals. In this paper, we follow a wave-function-based approach [N.I.…

Chemical Physics · Physics 2018-10-05 Timothy J. Callow , Nikitas I. Gidopoulos

The exact universal functional of integer charge leads to an extension to fractional charge asymptotically when it is applied to a system made of asymptotically separated densities. The extended functional is asymptotically local and is…

Chemical Physics · Physics 2024-12-17 Jing Kong

Occupation numbers for non-relativistic interacting particles are discussed within a functional integral formulation. We concentrate on zero temperature, where the Bogoliubov theory breaks down for strong couplings as well as for low…

Statistical Mechanics · Physics 2009-11-13 C. Wetterich

The density functional theory is extended to account for self-bound systems. To this end the Hohenberg-Kohn theorem is formulated for the intrinsic density and a Kohn-Sham like procedure for an $N$--body system is derived using the…

Nuclear Theory · Physics 2008-11-26 Nir Barnea

By introducing the self-energy density functionals for the dissipative interactions between the reduced system and its environment, we develop a time-dependent density-functional theory formalism based on an equation of motion for the…

Quantum Physics · Physics 2009-11-13 Xiao Zheng , Fan Wang , Chi Yung Yam , Yan Mo , GuanHua Chen

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

Given a vector space of microscopic quantum observables, density functional theory is formulated on its dual space. A generalized Hohenberg-Kohn theorem and the existence of the universal energy functional in the dual space are proven. In…

Nuclear Theory · Physics 2009-09-25 G. Rosensteel , Ts. Dankova

We present a perturbative approach within the scope of Kohn-Sham density functional theory (DFT). The method is based on the exact exchange-only optimized effective potential method, and correlation is included via perturbation expansion…

Chemical Physics · Physics 2007-05-23 P. Sule

There has been a high demand in rectifying the band gap under-estimation problem in density functional theory (DFT), while keeping the computational load at the same level as local density approximation. DFT-1/2 and shell DFT-1/2 are useful…

Materials Science · Physics 2025-07-08 Shengxin Yang , Jiangzhen Shi , Kan-Hao Xue , Jun-Hui Yuan , Xiangshui Miao

We introduce a novel energy functional for ground-state electronic-structure calculations. Its fundamental variables are the natural spin-orbitals of the implied singlet many-body wave function and their joint occupation probabilities. The…

Chemical Physics · Physics 2015-06-23 Ralph Gebauer , Morrel H. Cohen , Roberto Car