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We discuss a variational calculation for nuclear shell-model calculations and propose a new procedure for the energy-variance extrapolation (EVE) method using a sequence of the approximated wave functions obtained by the variational…

Hubbard-like Hamiltonians are widely used to describe on-site Coulomb interactions in magnetic and strongly-correlated solids, but there is much confusion in the literature about the form these Hamiltonians should take for shells of p and d…

Strongly Correlated Electrons · Physics 2016-02-10 M. E. A. Coury , S. L. Dudarev , W. M. C. Foulkes , A. P. Horsfield , Pui-Wai Ma , J. S. Spencer

Recently, the numerical solution of stiffly/highly-oscillatory Hamiltonian problems has been attacked by using Hamiltonian Boundary Value Methods (HBVMs) as spectral methods in time. While a theoretical analysis of this spectral approach…

Numerical Analysis · Mathematics 2025-01-20 Pierluigi Amodio , Luigi Brugnano , Felice Iavernaro

We explore the preparation of specific nuclear states on gate-based quantum hardware using variational algorithms. Large scale classical diagonalization of the nuclear shell model have reached sizes of $10^9 - 10^{10}$ basis states, but are…

Nuclear Theory · Physics 2022-07-11 I. Stetcu , A. Baroni , J. Carlson

The low-energy enhancement observed in the deexcitation $\gamma$-ray strength functions, attributed to magnetic dipole (M1) radiations, has spurred theoretical efforts to improve on its description. Among the most widely used approaches are…

Low-energy structure of even-even $^{108-116}$Cd isotopes is analyzed using a collective model that is based on the nuclear density functional theory. Spectroscopic properties are computed by solving the triaxial quadrupole collective…

Nuclear Theory · Physics 2022-12-19 K. Nomura , K. E. Karakatsanis

An improved prescription for choosing a transformed harmonic oscillator (THO) basis for use in configuration-space Hartree-Fock-Bogoliubov (HFB) calculations is presented. The new HFB+THO framework that follows accurately reproduces the…

Nuclear Theory · Physics 2011-05-12 M. V. Stoitsov , J. Dobaczewski , W. Nazarewicz , S. Pittel , D. J. Dean

Calculation of statistical properties of nuclei in a finite-temperature mean-field theory requires projection onto good particle number, since the theory is formulated in the grand canonical ensemble. This projection is usually carried out…

Nuclear Theory · Physics 2018-01-23 P. Fanto , Y. Alhassid , G. F. Bertsch

Variation after particle-number restoration is incorporated for the first time into the Hartree-Fock-Bogoliubov framework employing the Skyrme energy density functional with zero-range pairing. The resulting projected HFB equations can be…

Nuclear Theory · Physics 2008-11-26 M. V. Stoitsov , J. Dobaczewski , R. Kirchner , W. Nazarewicz , J. Terasaki

We present a machine-learning method for the nonparametric extraction of generalized parton distributions (GPDs) from Compton form factors (CFFs) constrained by experimental data. The method addresses the longstanding inverse problem posed…

High Energy Physics - Phenomenology · Physics 2026-05-26 Dima Watkins , Ishara Fernando , Dustin Keller

Considering the emblematic Hartree-Fock (HF) energy expression with single Slater determinant and the ortho-normal molecular orbits (MO) in it, expressed as a linear combination (LC) of atomic orbits (LCAO) basis set functions, the HF…

Chemical Physics · Physics 2019-09-04 Sandor Kristyan

The nuclear shell model is one of the successful models in theoretical understanding of nuclear structure. If a convenient effective interaction can be found between nucleons, various observables such as energies of nuclear states are…

Nuclear Theory · Physics 2020-01-24 Serkan Akkoyun , Nadjet Laouet , Fatima Benrachi

Multi-frequency, highly-oscillatory Hamiltonian problems derive from the mathematical modelling of many real life applications. We here propose a variant of Hamiltonian Boundary Value Methods (HBVMs), which is able to efficiently deal with…

Numerical Analysis · Mathematics 2018-07-17 L. Brugnano , J. I. Montijano , L. Rández

We have developed a symmetry-adapted modeling procedure for molecules and crystals. By using the completeness of multipoles to express spatial and time-reversal parity-specific anisotropic distributions, we can generate systematically the…

Materials Science · Physics 2023-05-12 Hiroaki Kusunose , Rikuto Oiwa , Satoru Hayami

Ab initio methods aim to solve the nuclear many-body problem with controlled approximations. Virtually exact numerical solutions for realistic interactions can only be obtained for certain special cases such as few-nucleon systems. Here we…

Nuclear Theory · Physics 2018-03-29 C. Forssén , B. D. Carlsson , H. T. Johansson , D. Sääf , A. Bansal , G. Hagen , T. Papenbrock

A variational method for computing conformational properties of molecules with Lennard-Jones potentials for the monomer-monomer interactions is presented. The approach is tailored to deal with angular degrees of freedom, {\it rotors}, and…

chem-ph · Physics 2016-08-31 Carsten Peterson , Ola Sommelius , Bo Söderberg

A high-fidelity finite volume scheme based on the BVD (boundary variation diminishing) concept is proposed in this study to solve the ideal magnetohydrodynamics (MHD) equations. A hybrid spatial reconstruction profile, consisting of a…

Fluid Dynamics · Physics 2024-04-24 Pan Chenxi , Song Sheng , Chen Chungang , Li Xingliang , Shen Xueshun , Xiao Feng

By application of a straightforward variational procedure we derive a simple, analytic upper bound on the ground-state energy eigenvalue of a semirelativistic Hamiltonian for (one or two) spinless particles which experience some…

High Energy Physics - Phenomenology · Physics 2009-10-28 Wolfgang Lucha , Franz F. SCHÖberl

In quantum embedding theories, a quantum many-body system is divided into localized clusters of sites which are treated with an accurate `high-level' theory and glued together self-consistently by a less accurate `low-level' theory at the…

Optimization and Control · Mathematics 2021-06-08 Yuehaw Khoo , Michael Lindsey

While quantum computing algorithms have been widely applied for electronic structure calculations, applications to molecular dynamics remain scarce. Complex and varied landscapes of molecular potential energy surfaces give rise to…

Quantum Physics · Physics 2026-04-02 K. Asnaashari , D. Bondarenko , R. V. Krems