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Population control is an essential component of any projector Monte Carlo algorithm. This control mechanism usually introduces a bias in the sampled quantities that is inversely proportional to the population size. In this paper, we…

Computational Physics · Physics 2021-04-28 Khaldoon Ghanem , Niklas Liebermann , Ali Alavi

We study the efficiency, precision and accuracy of all-electron variational and diffusion quantum Monte Carlo calculations using Slater basis sets. Starting from wave functions generated by Hartree-Fock and density functional theory, we…

Materials Science · Physics 2010-02-11 Norbert Nemec , Michael D. Towler , R. J. Needs

To better understand the capture process by a nanopore, we introduce an efficient Kinetic Monte Carlo (KMC) algorithm that can simulate long times and large system sizes by mapping the dynamic of a point-like particle in a 3D spherically…

Biological Physics · Physics 2021-03-22 Le Qiao , Maxime Ignacio , Gary W. Slater

The nuclear force acting between protons and neutrons is studied in the Monte Carlo simulations of the fundamental theory of the strong interaction, the quantum chromodynamics defined on the hypercubic space-time lattice. After a brief…

High Energy Physics - Phenomenology · Physics 2009-07-09 S. Aoki , T. Hatsuda , N. Ishii

We here apply the recently developed initiator density matrix quantum Monte Carlo (i-DMQMC) to a wide range of chemical environments using atoms and molecules in vacuum. i-DMQMC samples the exact density matrix of a Hamiltonian at finite…

Chemical Physics · Physics 2019-12-03 Hayley R. Petras , Sai Kumar Ramadugu , Fionn D. Malone , James J. Shepherd

Molecular dynamics (MD) simulation, which is considered an important tool for studying physical and chemical processes at the atomic scale, requires accurate calculations of energies and forces. Although reliable energies and forces can be…

Materials Science · Physics 2021-12-06 Van-Quyen Nguyen , Viet-Cuong Nguyen , Tien-Cuong Nguyen , Tien-Lam Pham

Full configuration interaction quantum Monte Carlo (FCIQMC) is a state-of-the-art stochastic electronic structure method, providing a methodology to compute FCI-level state energies of molecular systems within a quantum chemical basis.…

Chemical Physics · Physics 2022-04-29 Tonghuan Jiang , Wei Fang , Ali Alavi , Ji Chen

Model space quantum Monte Carlo (MSQMC) is an extension of full configuration interaction QMC (FCIQMC) that allows us to calculate quasi-degenerate and excited electronic states by sampling the effective Hamiltonian in the model space. We…

Chemical Physics · Physics 2017-12-29 Seiichiro L. Ten-no

In most simulations of nonrelativistic nuclear systems, the wave functions found solving the many-body Schr\"odinger equations describe the quantum-mechanical amplitudes of the nucleonic degrees of freedom. In those simulations the pionic…

Nuclear Theory · Physics 2018-10-01 Lucas Madeira , Alessandro Lovato , Francesco Pederiva , Kevin E. Schmidt

We introduce a numerical algorithm to stochastically sample the dual fermion perturbation series around the dynamical mean field theory, generating all topologies of two-particle interaction vertices. We show results in the weak and strong…

Strongly Correlated Electrons · Physics 2016-07-07 Sergei Iskakov , Andrey E. Antipov , Emanuel Gull

In a recent Letter we introduced Hellmann-Feynman operator sampling in diffusion Monte Carlo calculations. Here we derive, by evaluating the second derivative of the total energy, an efficient method for the calculation of the static…

Other Condensed Matter · Physics 2015-05-13 R. Gaudoin , J. M. Pitarke

In the context of Monte Carlo sampling for lattice models, the complexity of the energy landscape often leads to Markov chains being trapped in local optima, thereby increasing the correlation between samples and reducing sampling…

Statistical Mechanics · Physics 2024-10-29 Jiewei Ding , Jiahao Su , Ho-Kin Tang , Wing Chi Yu

We introduce a variational Monte Carlo framework that combines neural-network quantum states with the Lorentz integral transform technique to compute the dynamical properties of self-bound quantum many-body systems in continuous Hilbert…

Nuclear Theory · Physics 2025-04-30 Elad Parnes , Nir Barnea , Giuseppe Carleo , Alessandro Lovato , Noemi Rocco , Xilin Zhang

We present developments in the calculation of reduced density matrices (RDMs) in the full configuration interaction quantum Monte Carlo (FCIQMC) method. An efficient scheme is described to allow storage of RDMs across distributed memory,…

Computational Physics · Physics 2017-07-27 N. S. Blunt , George H. Booth , Ali Alavi

In recent years efficient algorithms have been developed for the numerical computation of relativistic single-particle path integrals in quantum field theory. Here, we adapt this "worldline Monte Carlo" approach to the standard problem of…

Efficient sampling from ensembles of Hamiltonian cycles is critical for predicting the thermodynamic properties of compact polymers, with applications including modeling protein and RNA folding and designing soft materials. Although…

Quantum Physics · Physics 2026-03-16 Davide Rattacaso , Daniel Jaschke , Antonio Trovato , Ilaria Siloi , Simone Montangero

Sequential Monte Carlo methods are typically not straightforward to implement on parallel architectures. This is because standard resampling schemes involve communication between all particles. The $\alpha$-sequential Monte Carlo method was…

Statistics Theory · Mathematics 2022-02-21 Deborshee Sen

A method for analytic continuation of imaginary-time correlation functions (here obtained in quantum Monte Carlo simulations) to real-frequency spectral functions is proposed. Stochastically sampling a spectrum parametrized by a large…

Strongly Correlated Electrons · Physics 2017-06-30 Anders W. Sandvik

Quantum Monte Carlo (QMC) is a powerful method to calculate accurate energies and forces for molecular systems. In this work, we demonstrate how we can obtain accurate QMC forces for the fluxional ethanol molecule at room temperature by…

We present a quantum Monte Carlo algorithm for the simulation of general quantum and classical many-body models within a single unifying framework. The algorithm builds on a power series expansion of the quantum partition function in its…

Statistical Mechanics · Physics 2020-08-05 Lalit Gupta , Tameem Albash , Itay Hen