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We apply a variational method devised for the nuclear many--body problem to the 1-dimensional Hubbard--model with nearest neighbor hopping and periodic boundary conditions. The test wave function consist for each state out of a single…

Strongly Correlated Electrons · Physics 2008-11-26 K. W. Schmid , T. Dahm , J. Margueron , H. Müther

We reexamine the recently introduced basis-set correction theory based on density-functional theory consisting in correcting the basis-set incompleteness error of wave-function methods using a density functional. We use a one-dimensional…

Chemical Physics · Physics 2022-02-16 Diata Traore , Emmanuel Giner , Julien Toulouse

A variational approach is used to calculate free energy and conformational properties in polyelectrolytes. The true bond and Coulomb potentials are approximated by a trial isotropic harmonic energy containing monomer-monomer force constants…

High Energy Physics - Lattice · Physics 2009-09-25 B. Jönsson , C. Peterson , B. Söderberg

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

We consider the problem of estimating the energy of a quantum state preparation for a given Hamiltonian in Pauli decomposition. For various quantum algorithms, in particular in the context of quantum chemistry, it is crucial to have energy…

Quantum Physics · Physics 2025-08-20 Alexander Gresch , Uğur Tepe , Martin Kliesch

A canonical formalism and constraint analysis for discrete systems subject to a variational action principle are devised. The formalism is equivalent to the covariant formulation, encompasses global and local discrete time evolution moves…

Mathematical Physics · Physics 2013-09-17 Bianca Dittrich , Philipp A Hoehn

Variational quantum eigensolver (VQE) is an efficient computational method promising chemical accuracy in electronic structure calculations on a universal-gate quantum computer. However, such a simple task as computing the electronic energy…

Chemical Physics · Physics 2018-06-04 Ilya G. Ryabinkin , Scott N. Genin , Artur F. Izmaylov

A variational treatment for a two-electron quantum dot (the artificial helium atom) is proposed which leads to exact answer for the ground state energy. Depending on the magnetic field value the singlet-triplet and triplet-triplet…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Subinoy Das , Pallab Goswami , J. K. Bhattacharjee

Calculations of ground-state and excited-state properties of materials have been one of the major goals of condensed matter physics. Ground-state properties of solids have been extensively investigated for several decades within the…

Strongly Correlated Electrons · Physics 2009-10-30 F. Aryasetiawan , O. Gunnarsson

We present a variational ansatz for the ground state of a strongly correlated Bose system. This ansatz goes beyond the Jastrow-Feenberg functional form and explicitly enforces coordination shells in the structure of the wavefunction. We…

Other Condensed Matter · Physics 2017-04-03 Y. Lutsyshyn

The nodal structure of bound-state wave functions for one-dimensional quantum systems with quartic energy-momentum dispersion and polynomial potentials is analysed by using the semiclassical approximation and variational approach. For…

Strongly Correlated Electrons · Physics 2026-03-06 E. V. Gorbar , B. E. Grinyuk , V. P. Gusynin

In this paper, we consider a pressure-velocity formulation of the heterogeneous wave equation and employ the constraint energy minimizing generalized multiscale finite element method (CEM-GMsFEM) to solve this problem. The proposed method…

Numerical Analysis · Mathematics 2020-10-06 Eric Chung , Sai-Mang Pun

In our previous article [4] an approach to derive Papapetrou equations for constrained electromagnetic field was demonstrated by use of field variational principles. The aim of current work is to present more universal technique of…

General Relativity and Quantum Cosmology · Physics 2007-06-29 A. T. Muminov

Many-body quantum-mechanical stationary states that have real valued wavefunctions are shown to satisfy a classical conservation of energy equation with a kinetic energy function. The terms in the equation depend on the probability…

Atomic Physics · Physics 2021-07-23 James P. Finley

Variational methods play an important role in the study of quantum many-body problems, both in the flavor of classical variational principles based on tensor networks as well as of quantum variational principles in near-term quantum…

Quantum Physics · Physics 2026-02-18 J. Eisert

A simple derivation of the static Gross-Pitaevskii (GP) equation is given from an energy variational principle. The result is then generalized heuristically to the time-dependent GP form. With this as background, a number of different…

Soft Condensed Matter · Physics 2007-05-23 G. G. N. Angilella , S. Bartalini , F. S. Cataliotti , I. Herrera , N. H. March , R. Pucci

An infinite sequence of potential well functions is considered. A trial wavefunction is used with the Schr$\ddot{\text{o}}$dinger equation to obtain an approximate ground state energy for each potential well function. We obtain an…

Quantum Physics · Physics 2018-03-07 Rodney O. Weber

Next-generation lithium-ion batteries with silicon anodes have positive characteristics due to higher energy densities compared to state-of-the-art graphite anodes. However, the large volume expansion of silicon anodes can cause high…

Numerical Analysis · Mathematics 2024-04-03 R. Schoof , G. F. Castelli , W. Dörfler

Hierarchical (first-order) structured deformations are studied from the variational point of view. The main contributions of the present research are the first steps, at the theoretical level, to establish a variational framework to…

Optimization and Control · Mathematics 2022-08-26 Ana Cristina Barroso , José Matias , Marco Morandotti , David R. Owen , Elvira Zappale

High accuracy helium wave functions based on exponentials with random coefficients are transformed into momentum space. The utility of the wave functions is demonstrated through calculation of the expectation value of various operators…

Atomic Physics · Physics 2009-11-10 J. Sapirstein