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This paper reports an implementation of Hartree-Fock linear response with complex orbitals for computing electronic spectra of molecules in a strong external magnetic fields. The implementation is completely general, allowing for…

Chemical Physics · Physics 2019-02-01 Sangita Sen , Kai K. Lange , Erik I. Tellgren

We present a rigorous derivation of the orbital magnetization for interacting electrons within the self-consistent Hartree-Fock approximation. Our method also allows us to derive formulas for the orbital magnetic susceptibility. The results…

Strongly Correlated Electrons · Physics 2026-02-16 Jian Kang , Minxuan Wang , Oskar Vafek

The orbital contribution to the magnetic properties of Fe in systems of decreasing dimensionality (bulk, surfaces, wire and free clusters) is investigated using a tight-binding hamiltonian in an $s, p,$ and $d$ atomic orbital basis set…

Materials Science · Physics 2008-04-22 Marie-Catherine Desjonquères , Cyrille Barreteau , Gabriel Autes , Daniel Spanjaard

The non-collinear spin-spiral density wave of the uniform electron gas is studied in the framework of Reduced-Density-Matrix-Functional Theory. For the Hartree-Fock approximation, which can be obtained as a limiting case of…

Strongly Correlated Electrons · Physics 2013-11-08 F. G. Eich , S. Kurth , C. R. Proetto , S. Sharma , E. K. U. Gross

We study the magnetic structure of the ground state of an itinerant Fermi system of spin-\nicefrac{1}{2} particles with magnetic dipole-dipole interactions. We show that, quite generally, the spin state of particles depend on its momentum,…

Quantum Gases · Physics 2010-07-02 Benjamin M. Fregoso , Eduardo Fradkin

The interaction between electronic and nuclear spins in the presence of external magnetic fields can be described by a spin Hamiltonian, with parameters obtained from first principles, electronic structure calculations. We describe an…

Materials Science · Physics 2019-04-10 Krishnendu Ghosh , He Ma , Vikram Gavini , Giulia Galli

We use a Hartree-Fock-Koopmans approach to study spin and interaction effects in a diffusive or chaotic quantum dot. In particular, we derive the statistics of the spacings between successive Coulomb-blockade peaks. We include fluctuations…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Y. Alhassid , S. Malhotra

The contribution of the spin-orbit interaction in Hartree-Fock calculations for closed shell nuclei is studied. We obtain explicit expressions for the finite range spin-orbit force. New terms with respect to the traditional spin-orbit…

Nuclear Theory · Physics 2009-11-06 Ana R. Bautista , Giampaolo Co' , Antonio M. Lallena

The spherical Hartree-Fock approximation is applied to the $abinitio$ no-core shell model, with a realistic effective nucleon-nucleon interaction in order to investigate the range of its utility. Hartree-Fock results for binding energies,…

Nuclear Theory · Physics 2009-11-10 M. A. Hasan , J. P. Vary , P. Navratil

Fractional-spin errors are inherent in all current approximate density functionals, including Hartree-Fock theory, and their origin has been related to strong static correlation effects. The conventional way to encode fractional-spin…

Four-component Dirac Hartree--Fock is an accurate mean-field method for treating molecular systems where relativistic effects are important. However, the computational cost and complexity of the two-electron interaction makes this method…

Chemical Physics · Physics 2021-06-08 Shichao Sun , Torin Stetina , Tianyuan Zhang , Hang Hu , Edward F. Valeev , Qiming Sun , Xiaosong Li

We use relativistic Hartree-Fock and correlation potential methods to calculate nuclear spin-dependent parity non-conserving amplitudes (dominated by the nuclear anapole moment) between hyperfine structure components of the ground state of…

Atomic Physics · Physics 2015-06-03 V. A. Dzuba , V. V. Flambaum

An expression for the square of the spin operator expectation value, \textless{} S^2\textgreater{}, is obtained for a general complex Hartree-Fock (GCHF) wave function and decomposed into four contributions: The main one whose expression is…

Quantum Physics · Physics 2015-09-08 Patrick Cassam-Chenaï

Noncollinear magnetic states in clusters are studied by using the single-band Hubbard Hamiltonian. The unrestricted Hartree-Fock (UHF) approximation is considered without imposing any symmetry constraints neither to the size or orientation…

Strongly Correlated Electrons · Physics 2009-10-31 Miguel A. Ojeda , J. Dorantes-Davila , G. M. Pastor

Gravitational waves provide us with a new window into our Universe, and have already been used to place strong constrains on the existence of light scalar fields, which are a common feature in many alternative theories of gravity. However,…

General Relativity and Quantum Cosmology · Physics 2021-10-28 Philippe Brax , Anne-Christine Davis , Scott Melville , Leong Khim Wong

Spin-1/2 particles can be used to study inertial and gravitational effects by means of interferometers, particle accelerators, and ultimately quantum systems. These studies require, in general, knowledge of the Hamiltonian and of the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 D. Singh , G. Papini

Building upon the worldline effective field theory (EFT) formalism for spinning bodies developed for the Post-Newtonian regime, we generalize the EFT approach to Post-Minkowskian (PM) dynamics to include rotational degrees of freedom in a…

High Energy Physics - Theory · Physics 2022-05-30 Zhengwen Liu , Rafael A. Porto , Zixin Yang

We explore the impact of optimizations of the single-particle basis on the convergence behavior and robustness of ab initio no-core shell model calculations. Our focus is on novel basis sets defined by the natural orbitals of a correlated…

Nuclear Theory · Physics 2019-03-27 Alexander Tichai , Julius Müller , Klaus Vobig , Robert Roth

We report results for the ground state energies and wave functions obtained by projecting spatially unrestricted Hartree Fock states to eigenstates of the total spin and the angular momentum for harmonic quantum dots with $N\leq 12$…

Mesoscale and Nanoscale Physics · Physics 2011-10-10 U. De Giovannini , F. Cavaliere , R. Cenni , M. Sassetti , B. Kramer

Time-dependent Hartree-Fock theory is used to describe density oscillations of symmetry-unrestricted two-dimensional nanostructures. In the small amplitude limit the results reproduce those obtained within a perturbative approach such as…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Antonio Puente , Llorenç Serra , Vidar Gudmundsson
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