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Quantum Monte Carlo methods provide in principle an accurate treatment of the many-body problem of the ground and excited states of condensed systems. In practice, however, uncontrolled errors such as those arising from the fixed-node and…

Materials Science · Physics 2012-03-27 William W. Tipton , Neil D. Drummond , Richard G. Hennig

We report diffusion quantum Monte Carlo calculations of three-dimensional Wigner crystals in the density range r_s=100-150. We have tested different types of orbital for use in the approximate wave functions but none improve upon the simple…

Strongly Correlated Electrons · Physics 2008-01-03 N. D. Drummond , Z. Radnai , J. R. Trail , M. D. Towler , R. J. Needs

High-order virtual excitations play an important role in microscopic models of nuclear reactions at intermediate energies. However, the factorial growth of their complexity has prevented their consistent inclusion in ab initio many-body…

Nuclear Theory · Physics 2025-05-15 Stefano Brolli , Carlo Barbieri , Enrico Vigezzi

The behavior of an isolated dilute granular gas near the threshold of its clustering instability is investigated by means of fluctuating hydrodynamics and the direct simulation Monte Carlo method. The theoretical predictions from the former…

Statistical Mechanics · Physics 2007-05-23 J. Javier Brey , M. J. Ruiz-Montero

A continuous-time formulation of the Diffusion Monte Carlo method for lattice models is presented. In its simplest version, without the explicit use of trial wavefunctions for importance sampling, the method is an excellent tool for…

Strongly Correlated Electrons · Physics 2009-11-10 Olav F. Syljuasen

A computational model is presented to calculate the ground state energy of neutral and charged excitons confined in semiconductor quantum dots. The model is based on the variational Quantum Monte Carlo method and effective mass…

Mesoscale and Nanoscale Physics · Physics 2021-02-03 Josep Planelles , Juan I. Climente

The essence of atomic structure theory, quantum chemistry, and computational materials science is solving the multi-electron stationary Schr\"odinger equation. The Quantum Monte Carlo-based neural network wave function method has surpassed…

Atomic Physics · Physics 2023-12-27 JinDe Liu , Chenglong Qin , Xi He , Gang Jiang

A one-dimensional model of electrons locally coupled to spin-1/2 degrees of freedom is studied by numerical techniques. The model is one in the class of $dynamic$ $Hubbard$ $models$ that describe the relaxation of an atomic orbital upon…

Strongly Correlated Electrons · Physics 2009-11-07 J. E. Hirsch

It is demonstrated using Monte Carlo simulation that in different nucleus$-$nucleus collision samples, the increase of the fluctuation of event factorial moments with decreasing phase space scale, called erraticity, is still dominated by…

High Energy Physics - Phenomenology · Physics 2009-11-07 Liu Fuming , Liao Hongbo , Liu Ming , Liu Feng , Liu Lianshou

Density matrix quantum Monte Carlo (DMQMC) is used to sample exact-on-average $N$-body density matrices for uniform electron gas systems of up to 10$^{124}$ matrix elements via a stochastic solution of the Bloch equation. The results of…

Strongly Correlated Electrons · Physics 2016-09-14 Fionn D. Malone , N. S. Blunt , Ethan W. Brown , D. K. K. Lee , J. S. Spencer , W. M. C. Foulkes , James J. Shepherd

Diffusion Monte Carlo (DMC) calculations are performed on the monocyclic and bicyclic forms of m-benzyne, which are the equilibrium structures at the CCSD(T) and CCSD levels of coupled cluster theory. We employed multi-configuration…

Chemical Physics · Physics 2009-11-13 W. A. Al-Saidi , C. J. Umrigar

We present a study of spin-unpolarized and spin-polarized two-dimensional uniform electron liquids using variational and diffusion quantum Monte Carlo (VMC and DMC) methods with Slater-Jastrow-backflow trial wave functions. Ground-state VMC…

Strongly Correlated Electrons · Physics 2025-11-11 Sam Azadi , N. D. Drummond , S. M. Vinko

Fixed-node diffusion Monte Carlo (FNDMC) is a stochastic quantum many-body method that has a great potential in electronic structure theory. We examine how FNDMC satisfies exact constraints, linearity and derivative discontinuity of total…

Chemical Physics · Physics 2019-10-16 Matej Ditte , Matus Dubecky

The variational Monte Carlo method is used to evaluate the ground-state energy of the confined hydrogen molecule, H_2. Accordingly, we considered the case of hydrogen molecule confined by a hard prolate spheroidal cavity when the nuclear…

Atomic and Molecular Clusters · Physics 2015-09-10 S. B. Doma , F. N. El-Gammal , A. A. Amer

Concentrating on zero temperature Quantum Monte Carlo calculations of electronic systems, we give a general description of the theory of finite size extrapolations of energies to the thermodynamic limit based on one and two-body correlation…

Thermalization of heavy quarks in the quark-gluon plasma (QGP) is one of the most promising phenomena for understanding the strong interaction. The energy loss and momentum broadening at low momentum can be well described by a stochastic…

High Energy Physics - Phenomenology · Physics 2024-05-01 Xiaojian Du , Wenyang Qian

It has become increasingly feasible to use quantum Monte Carlo (QMC) methods to study correlated fermion systems for realistic Hamiltonians. We give a summary of these techniques targeted at researchers in the field of correlated electrons,…

Strongly Correlated Electrons · Physics 2016-08-24 Lucas K. Wagner , David M. Ceperley

Quantum Monte Carlo (QMC) is an advanced simulation methodology for studies of manybody quantum systems. In this review, we focus on the electronic structure QMC, i.e., methods relevant for systems described by the electron-ion…

Other Condensed Matter · Physics 2010-08-16 Michal Bajdich , Lubos Mitas

We study the electronic excitation spectra in solid molecular hydrogen (phase I) at ambient temperature and 5-90 GPa pressures using Quantum Monte Carlo methods and Many-Body Perturbation Theory. In this range, the system changes from a…

Materials Science · Physics 2024-05-21 Vitaly Gorelov , Markus Holzmann , David M. Ceperley , Carlo Pierleoni

We report on the first quantum Monte Carlo calculations of helium isotopes with fully propagated theoretical uncertainties from the interaction to the many-body observables. To achieve this, we build emulators for solutions to the Faddeev…