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Related papers: Quantum Monte Carlo with Jastrow-valence-bond wave…

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We propose using the wave function generated by the quantum selected configuration interaction (QSCI) method as the trial wave function in phaseless auxiliary-field quantum Monte Carlo (ph-AFQMC). In the QSCI framework, electronic…

We present a variational function that targets excited states directly based on their position in the energy spectrum, along with a Monte Carlo method for its evaluation and minimization whose cost scales polynomially for a wide class of…

Strongly Correlated Electrons · Physics 2016-01-22 Luning Zhao , Eric Neuscamman

Variational Monte Carlo calculations of the quasielectron and quasihole excitation energies in the fractional quantum Hall effect have been carried out at filling fractions $\nu=1/3$, 1/5, and 1/7. For the quasielectron both the trial wave…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 V. Melik-Alaverdian , N. E. Bonesteel

We show how efficient loop updates, originally developed for Monte Carlo simulations of quantum spin systems at finite temperature, can be combined with a ground-state projector scheme and variational calculations in the valence bond basis.…

Strongly Correlated Electrons · Physics 2010-07-14 A. W. Sandvik , H. G. Evertz

We review the use of continuum quantum Monte Carlo (QMC) methods for the calculation of energy gaps from first principles, and present a broad set of excited-state calculations carried out with the variational and fixed-node diffusion QMC…

Materials Science · Physics 2018-08-22 Ryan J. Hunt , Marcin Szyniszewski , Genki I. Prayogo , Ryo Maezono , Neil D. Drummond

The energy variance optimization algorithm over a fixed ensemble of configurations in variational Monte Carlo is formally identical to a problem of fitting data: we reexamine it from a statistical maximum-likelihood point of view. We detect…

Atomic and Molecular Clusters · Physics 2009-11-07 Dario Bressanini , Gabriele Morosi , Massimo Mella

The behavior of the one-dimensional random-force-driven Burgers equation is investigated in the path integral formalism on a discrete space-time lattice. We show that by means of Monte Carlo methods one may evaluate observables, such as…

High Energy Physics - Lattice · Physics 2010-11-05 P. Düben , D. Homeier , K. Jansen , D. Mesterhazy , G. Münster

We have studied the spin-polarized three-dimensional homogeneous electron gas using the diffusion quantum Monte Carlo method, with trial wave functions including backflow and three-body correlations in the Jastrow factor, and we have used…

Strongly Correlated Electrons · Physics 2013-08-28 G G Spink , R J Needs , N D Drummond

We present a new class of algorithms for performing valence-bond quantum Monte Carlo of quantum spin models. Valence-bond quantum Monte Carlo is a T=0 Monte Carlo method based on sampling of a set of operator-strings that can be viewed as…

Computational Physics · Physics 2014-09-16 Andreas Deschner , Erik S. Sørensen

We explore the application of an extrapolative method that yields very accurate total and relative energies from variational and diffusion quantum Monte Carlo (VMC and DMC) results. For a trial wave function consisting of a small…

Computational Physics · Physics 2024-04-25 Seyed Mohammadreza Hosseini , Ali Alavi , Pablo Lopez Rios

We present the first open access version of the QMeCha (Quantum MeCha) code, a quantum Monte Carlo (QMC) package developed to study many-body interactions between different types of quantum particles, with a modular and easy-to-expand…

We review a recent approach for the simulation of many-body interacting systems based on an efficient generalization of the Lanczos method for Quantum Monte Carlo simulations. This technique allows to perform systematic corrections to a…

Strongly Correlated Electrons · Physics 2007-05-23 Sandro Sorella

A precise discussion of a single bond requires consideration of two-particle wave function for the particles involved. Here we define and determine rigorously the intrinsic covalency and connected characteristics on the canonical example of…

Strongly Correlated Electrons · Physics 2022-11-01 Maciej Hendzel , Maciej Fidrysiak , Józef Spałek

We demonstrate a scaling method for non-Markovian Monte Carlo wave-function simulations used to study open quantum systems weakly coupled to their environments. We derive a scaling equation, from which the result for the expectation values…

Quantum Physics · Physics 2009-11-10 J. Piilo , S. Maniscalco , A. Messina , F. Petruccione

An inhomogeneous backflow transformation for many-particle wave functions is presented and applied to electrons in atoms, molecules, and solids. We report variational and diffusion quantum Monte Carlo VMC and DMC energies for various…

Computational Physics · Physics 2008-01-04 P. Lopez-Rios , A. Ma , N. D. Drummond , M. D. Towler , R. J. Needs

Bond stretching mimics different levels of electron correlation and provides a challenging testbed for approximate many-body computational methods. Using the recently developed phaseless auxiliary-field quantum Monte Carlo (AF QMC) method,…

Computational Physics · Physics 2007-10-10 W. A. Al-Saidi , Shiwei Zhang , Henry Krakauer

In this work, we investigate the fidelity of orbital optimization in variational Monte Carlo to improve diffusion Monte Carlo results on correlated magnetic systems, using CrSBr as a model system. We compare the performance of different…

Strongly Correlated Electrons · Physics 2026-04-27 Cody A. Melton , Jaron T. Krogel

Quantum Monte Carlo approaches such as the diffusion Monte Carlo (DMC) method are among the most accurate many-body methods for extended systems. Their scaling makes them well suited for defect calculations in solids. We review the various…

Materials Science · Physics 2014-04-23 William D. Parker , John W. Wilkins , Richard G. Hennig

Quantum Monte Carlo simulations of interacting electrons in solids often use Slater-Jastrow trial wave functions. The Jastrow function takes into account correlations between pairs of electrons. In simulations of solids, it is common to use…

Materials Science · Physics 2007-05-23 A. Garcia-Lekue , M. Nekovee , J. M. Pitarke , R. Gaudoin

Variational quantum Monte Carlo (QMC) is an ab-initio method for solving the electronic Schr\"odinger equation that is exact in principle, but limited by the flexibility of the available ansatzes in practice. The recently introduced deep…

Computational Physics · Physics 2021-03-26 Zeno Schätzle , Jan Hermann , Frank Noé