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We compare two different approaches to investigations of many-electron systems. The first is the Hartree-Fock (HF) method and the second is the Density Functional Theory (DFT). Overview of the main features and peculiar properties of the HF…

Materials Science · Physics 2009-11-07 M. Ya. Amusia , A. Z. Msezane , V. R. Shaginyan

We present a density matrix approach for computing global solutions of Hartree-Fock theory, based on semidefinite programming (SDP), that gives upper and lower bounds on the Hartree-Fock energy of quantum systems. Equality of the upper- and…

Chemical Physics · Physics 2014-02-11 Srikant Veeraraghavan , David A. Mazziotti

The density-constrained time-dependent Hartree-Fock (DC-TDHF) theory is a fully microscopic approach for calculating heavy-ion interaction potentials and fusion cross sections below and above the fusion barrier. We discuss recent…

Nuclear Theory · Physics 2014-02-07 A. S. Umar , V. E. Oberacker , R. Keser , J. A. Maruh , P. -G. Reinhard

Precise solutions of the Hartree-Fock equations for the ground state of the hydrogen molecule are obtained for a wide range of internuclear distances R by means of a two-dimensional fully numerical mesh computational method. The spatial…

Atomic Physics · Physics 2007-05-23 Mikhail V. Ivanov

We present a new method to accelerate real time-time dependent density functional theory (rt-TDDFT) calculations with hybrid exchange-correlation functionals. For large basis set, the computational bottleneck for large scale calculations is…

Computational Physics · Physics 2019-07-24 Weile Jia , Lin Lin

We present a multigrid scheme for the solution of finite-element Hartree-Fock equations for diatomic molecules. It is shown to be fast and accurate, the time effort depending linearly on the number of variables. Results are given for the…

Computational Physics · Physics 2007-05-23 O. Beck , D. Heinemann , D. Kolb

In periodic systems, the Hartree-Fock (HF) exchange energy exhibits the slowest convergence of all HF energy components as the system size approaches the thermodynamic limit. We demonstrate that the recently proposed staggered mesh method…

Computational Physics · Physics 2024-02-22 Stephen Jon Quiton , Hamlin Wu , Xin Xing , Lin Lin , Martin Head-Gordon

The evaluation of exact (Hartree--Fock, HF) exchange operator is a crucial ingredient for the accurate description of electronic structure in periodic systems through ab initio and hybrid density functional approaches. An efficient…

Chemical Physics · Physics 2020-10-28 Xiao Wang , Cannada A. Lewis , Edward F. Valeev

Few-electron systems confined in two-dimensional parabolic quantum dots at high magnetic fields are studied by the Hartree-Fock (HF) and exact diagonalization methods. A generalized multicenter Gaussian basis is proposed in the HF method. A…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 B. Szafran , S. Bednarek , J. Adamowski , M. B. Tavernier , E. Anisimovas , F. M. Peeters

A simple approximation within the framework of the hybrid methods for the calculation of the electronic structure of solids is presented. By considering only the diagonal elements of the perturbation operator (Hartree-Fock exchange minus…

Materials Science · Physics 2012-01-31 Fabien Tran

A modified version of the Moller-Plesset approach for obtaining the correlation energy associated to a Hartree-Fock ground state is proposed. The method is tested in a model of interacting fermions that allows for an exact solution. Using…

Materials Science · Physics 2016-10-12 Alejandro Cabo , Francisco Claro , Eduardo Menendez-Proupin

The quantum imaginary time evolution (QITE) algorithm is a direct implementation of the classical imaginary time evolution algorithm on quantum computer. We implement the QITE algorithm for the case of nuclear Hartree-Fock equations in a…

Nuclear Theory · Physics 2024-12-02 Yang Hong Li , Jim Al-Khalili , Paul Stevenson

The energy density functional (EDF) method is very widely used in nuclear physics, and among the various existing functionals those based on the relativistic Hartree (RH) approximation are very popular because the exchange contributions…

Nuclear Theory · Physics 2014-05-16 Nguyen Van Giai , Haozhao Liang , Huai-Qiang Gu , Wenhui Long , Jie Meng

Relativistic Hartree-Fock method together with many-body perturbation theory and configuration interaction techniques are used to calculate relativistic energy shifts for frequencies of the strong electric dipole transitions of C III, C IV,…

Atomic Physics · Physics 2007-10-26 I. M. Savukov , V. A. Dzuba

Efficient hybrid DFT simulations of solid state materials would be extremely beneficial for computational chemistry and materials science, but is presently bottlenecked by difficulties in computing Hartree-Fock (HF) exchange with plane wave…

Chemical Physics · Physics 2024-10-30 Yuanheng Wang , Diptarka Hait , Pablo A. Unzueta , Juncheng Harry Zhang , Todd J. Martínez

We derive a multiconfigurational time-dependent Hartree theory for systems with particle conversion. In such systems particles of one kind can convert to another kind and the total number of particles varies in time. The theory thus extends…

Quantum Physics · Physics 2009-02-07 Ofir E. Alon , Alexej I. Streltsov , Lorenz S. Cederbaum

The multiconfigurational time-dependent Hartree method (MCTDH) [Chem. Phys. Lett. {\bf 165}, 73 (1990); J. Chem. Phys. {\bf 97}, 3199 (1992)] is celebrating nowadays entering its third decade of tackling numerically-exactly a broad range of…

The energy levels of the first few low-lying states of helium and lithium atoms in intense magnetic fields up to $\approx 10^8-10^9$~T are calculated in this study. A pseudospectral method is employed for the computational procedure. The…

Quantum Physics · Physics 2014-06-11 Anand Thirumalai , Jeremy S. Heyl

We analyze the details of mass exchange in the vicinity of the Coulomb barrier for heavy-ion collisions involving neutron-rich nuclei using the time-dependent Hartree-Fock (TDHF) theory. We discuss the time-dependence of transfer and show…

Nuclear Theory · Physics 2008-11-26 A. S. Umar , V. E. Oberacker , J. A. Maruhn

Density functional theory (DFT), one of the most widely utilized methods available to computational chemistry, fails to describe systems with statically correlated electrons. To address this shortcoming, in previous work we transformed DFT…

Chemical Physics · Physics 2023-01-02 Daniel Gibney , Jan-Niklas Boyn , David A. Mazziotti