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Standard density functional approximations often give questionable results for odd-electron radical complexes, with the error typically attributed to self-interaction. In density corrected density functional theory (DC-DFT), certain classes…

Chemical Physics · Physics 2015-06-19 Min-Cheol Kim , Eunji Sim , Kieron Burke

We present a $\Delta$-machine learning model for obtaining Kohn-Sham accuracy from orbital-free density functional theory (DFT) calculations. In particular, we employ a machine learned force field (MLFF) scheme based on the kernel method to…

Chemical Physics · Physics 2023-10-11 Shashikant Kumar , Xin Jing , John E. Pask , Andrew J. Medford , Phanish Suryanarayana

The main purpose of this paper is to derive a new perturbation theory (PT) that has converging series. Such series arise in the nonlocal scalar quantum field theory (QFT) with fractional power potential. We construct PT for the generating…

High Energy Physics - Theory · Physics 2023-09-26 Nikita A. Ignatyuk , Stanislav L. Ogarkov , Daniel V. Skliannyi

We resolve a fundamental issue associated with the conventional Kohn-Sham formulation of real-time time-dependent density functional theory. We show that unphysical multielectron excitations, generated during time propagation of the…

Computational Physics · Physics 2020-01-16 Xiaoning Zang , Udo Schwingenschlogl , Mark T. Lusk

Bridging the gap between first principles methods and empirical schemes, the density functional based tight-binding method (DFTB) has become a versatile tool in predictive atomistic simulations over the past years. One of the major…

Materials Science · Physics 2015-04-02 Vitalij Lutsker , Balint Aradi , Thomas A. Niehaus

The present work is a study of the unitarity problem for Quantum Mechanics at Planck Scale considered as Quantum Mechanics with Fundamental Length (QMFL).In the process QMFL is described as deformation of a well-known Quantum Mechanics…

General Relativity and Quantum Cosmology · Physics 2007-05-23 A. E. Shalyt-Margolin

In approximate Kohn-Sham density-functional theory, self-interaction manifests itself as the dependence of the energy of an orbital on its fractional occupation. This unphysical behavior translates into qualitative and quantitative errors…

Materials Science · Physics 2010-09-28 Ismaila Dabo , Andrea Ferretti , Nicolas Poilvert , Yanli Li , Nicola Marzari , Matteo Cococcioni

Density functional theory (DFT) became a universal approach to compute ground-state and excited configurations of many-electron systems held together by an external one-body potential in condensed-matter, atomic, and molecular physics. At…

Nuclear Theory · Physics 2011-09-30 J. Dobaczewski

Orbital-free density functional theory (OF-DFT) constitutes a computationally highly effective tool for modeling electronic structures of systems ranging from room-temperature materials to warm dense matter. Its accuracy critically depends…

We formulate and implement Cyclic Density Functional Theory (Cyclic DFT) -- a self-consistent first principles simulation method for nanostructures with cyclic symmetries. Using arguments based on Group Representation Theory, we rigorously…

Materials Science · Physics 2017-03-16 Amartya S. Banerjee , Phanish Suryanarayana

An interesting fundamental problem in density-functional theory of electronic structure of matter is to construct the exact Kohn-Sham (KS) potential for a given density. The exact potential can then be used to assess the accuracy of…

Atomic and Molecular Clusters · Physics 2019-05-22 Ashish Kumar , Rabeet Singh , Manoj K. Harbola

Degenerate dynamical systems are characterized by symplectic structures whose rank is not constant throughout phase space. Their phase spaces are divided into causally disconnected, nonoverlapping regions such that there are no classical…

High Energy Physics - Theory · Physics 2015-06-04 Fiorenza de Micheli , Jorge Zanelli

Nuclear density functional theory (DFT) is one of the main theoretical tools used to study the properties of heavy and superheavy elements, or to describe the structure of nuclei far from stability. While on-going efforts seek to better…

Nuclear Theory · Physics 2015-12-23 N. Schunck , J. D. McDonnell , D. Higdon , J. Sarich , S. M. Wild

We propose a machine learning based approach to develop the exchange-correlation potential of time dependent density functional theory (TDDFT). The neural network projection from the time-varying electron densities to the corresponding…

Computational Physics · Physics 2020-05-20 Yasumitsu Suzuki , Ryo Nagai , Jun Haruyama

Adsorbed transition metal atoms can have partially filled $d$- or $f$-shells due to strong on-site Coulomb interaction. Capturing all effects originating from electron correlation in such strongly correlated systems is a challenge for…

Strongly Correlated Electrons · Physics 2018-01-17 Marc Philipp Bahlke , Michael Karolak , Carmen Herrmann

We propose a local real-space formulation for orbital-free DFT with density dependent kinetic energy functionals and a unified variational framework for computing the configurational forces associated with geometry optimization of both…

Materials Science · Physics 2015-06-15 Sambit Das , Mrinal Iyer , Vikram Gavini

Using density functional theory, we investigate fluctuations of the ground state energy of spin-polarized, disordered quantum dots in the metallic regime. To compare to experiment, we evaluate the distribution of addition energies and find…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 K. Hirose , F. Zhou , N. Wingreen

The standard model of classical Density Functional Theory for pair potentials consists of a hard-sphere functional plus a mean-field term accounting for long ranged attraction. However, most implementations using sophisticated Fundamental…

Computational Physics · Physics 2021-01-04 James F. Lutsko , Cédric Schoonen

Density functional theory (DFT), the most widely adopted method in modern computational chemistry, fails to describe accurately the electronic structure of strongly correlated systems. Here we show that DFT can be formally and practically…

Chemical Physics · Physics 2022-04-18 Daniel Gibney , Jan-Niklas Boyn , David A. Mazziotti

In standard Kohn-Sham (KS) density-functional theory (DFT) the valence band satellites in Ni and Pd are missing, the band widths in Ni and Na are too large, and the formation of lower and upper Hubbard bands in SrVO$_3$ is not described.…

Materials Science · Physics 2022-12-27 Frank Freimuth , Stefan Blügel , Yuriy Mokrousov
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