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We present recent developments of the NTChem program for performing large scale hybrid Density Functional Theory calculations on the supercomputer Fugaku. We combine these developments with our recently proposed Complexity Reduction…

It is known that the separation of electrons into spinons and chargons, the spin-charge separation, plays a decisive role when describing strongly correlated density distributions in one dimension. In this manuscript, we extend the…

Chemical Physics · Physics 2014-04-07 Daniel Vieira

Faithful representations of atomic environments and general models for regression can be harnessed to learn electron densities that are close to the ground state. One of the applications of data-derived electron densities is to orbital-free…

Materials Science · Physics 2019-03-01 Andrew T. Fowler , Chris J. Pickard , James A. Elliott

Reporting extensions of a recently developed approach to density functional theory with correct long-range be-havior (Phys. Rev. Lett. 94, 043002 (2005)). The central quantities are a splitting functional gamma[n] and a complementary…

Materials Science · Physics 2017-09-13 Ester Livshits , Roi Baer

The Hohenberg-Kohn (HK) theorem is one of the most fundamental theorems of quantum mechanics, and constitutes the basis for the very successful density-functional approach to inhomogeneous interacting many-particle systems. Here we show…

Materials Science · Physics 2009-11-11 K. Capelle , C. A. Ullrich , G. Vignale

The Hubbard model provides a test bed to investigate the complex behaviour arising from electron-electron interaction in strongly-correlated systems and naturally emerges as the foundation model for lattice density functional theory (DFT).…

Strongly Correlated Electrons · Physics 2025-01-29 Eoghan Cronin , Rajarshi Tiwari , Stefano Sanvito

Exact density-functional theory is reconstructed here from its convex variational structure as two parallel exact ensemble hierarchies: an interacting hierarchy rooted in Lieb's ensemble formulation and a noninteracting hierarchy rooted in…

Chemical Physics · Physics 2026-05-01 Nan Sheng

The calculation of the band-gap by density-functional theory (DFT) methods is examined by considering the behavior of the energy as a function of number of electrons. It is found that the incorrect band-gap prediction with most approximate…

Materials Science · Physics 2009-11-13 Aron J. Cohen , Paula Mori-Sánchez , Weitao Yang

Kohn-Sham Density Functional Theory (KS-DFT) provides the exact ground state energy and electron density of a molecule, contingent on the as-yet-unknown universal exchange-correlation (XC) functional. Recent research has demonstrated that…

The widespread use of (generalized) Kohn-Sham density functional theory (KS-DFT) lies in the fact that hierarchical sets of approximations of the exchange-correlation (XC) energy functional can be designed, offering versatile choices to…

Materials Science · Physics 2023-01-31 Igor Ying Zhang , Xinguo Ren

The analytic energy gradients in the atomic orbital representation have recently been published (J. Chem. Phys. 146, 014102, 2017) within the framework of the natural orbital functional theory (NOFT). We provide here an alternative…

Chemical Physics · Physics 2018-02-19 Ion Mitxelena , Mario Piris

To describe excited states, the electron density alone being insufficient, we use the noninteracting reference density matrix $\gamma_{s}({\bf x},{\bf x}')$ based on the recently established foundation for the $\Delta SCF$ theory, in which…

Chemical Physics · Physics 2024-08-20 Weitao Yang , Yichen Fan

We demonstrate how the separation of the total energy of a self-bound system into a functional of the internal one-body Fermionic density and a function of an arbitrary wave vector describing the center-of-mass kinetic energy can be used to…

Nuclear Theory · Physics 2009-12-14 J. Messud , M. Bender , E. Suraud

The Hohenberg-Kohn theorem and the Kohn-Sham equations, which are at the basis of the Density Functional Theory, are reformulated in terms of a particular many-body density, which is translational invariant and therefore is relevant for…

Nuclear Theory · Physics 2021-09-29 A. Kievsky , G. Orlandini , M. Gattobigio

The formalism of Kohn and Sham uses a specific (model) hamiltonian which highly simplifies the many-electron problem to that of noninteracting fermions. The theorem of Hohenberg and Kohn tells us that, for a given ground state density, this…

Materials Science · Physics 2007-07-05 Paola Gori-Giorgi , Julien Toulouse , Andreas Savin

Local density approximation (LDA) to the density functional theory (DFT) has continuous derivative of total energy as a number of electrons function and continuous exchange-correlation potential, while in exact DFT both should be…

Strongly Correlated Electrons · Physics 2010-06-28 V. I. Anisimov , A. V. Kozhevnikov , M. A. Korotin , A. V. Lukoyanov , D. A. Khafizullin

Machine learning is employed to build an energy density functional for self-bound nuclear systems for the first time. By learning the kinetic energy as a functional of the nucleon density alone, a robust and accurate orbital-free density…

Nuclear Theory · Physics 2022-03-21 X. H. Wu , Z. X. Ren , P. W. Zhao

We propose exchanging the energy functionals in ground-state DFT with physically equivalent exact force expressions as a new promising route towards approximations to the exchange-correlation potential and energy. In analogy to the usual…

Quantum mechanical methods based on the density functional theory (DFT) offer a realistic possibility of first-principles design of organic donor-acceptor systems and engineered band-gap materials. This promise is contingent upon the…

Chemical Physics · Physics 2013-12-03 Marcin Modrzejewski , Grzegorz Chałasiński , Małgorzata M. Szczęśniak

We propose a novel extension to symmetrized neural network operators by incorporating fractional and mixed activation functions. This study addresses the limitations of existing models in approximating higher-order smooth functions,…

Machine Learning · Statistics 2025-01-22 Rômulo Damasclin Chaves dos Santos , Jorge Henrique de Oliveira Sales
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