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We introduce an efficient lattice regularization scheme for quantum Monte Carlo calculations of realistic electronic systems. The kinetic term is discretized by a finite difference Laplacian with two mesh sizes, a and a', where a'/a is an…

其他凝聚态物理 · 物理学 2009-11-11 Michele Casula , Claudia Filippi , Sandro Sorella

The Monte Carlo Hamiltonian method developed recently allows to investigate ground state and low-lying excited states of a quantum system, using Monte Carlo algorithm with importance sampling. However, conventional MC algorithm has some…

高能物理 - 格点 · 物理学 2018-01-17 Xiang-Qian Luo , Xiao-Ni Cheng , Helmut Kroger

We extend the event-chain Monte Carlo algorithm from hard-sphere interactions to the micro-canonical ensemble (constant potential energy) for general potentials. This event-driven Monte Carlo algorithm is non-local, rejection-free, and…

统计力学 · 物理学 2022-08-31 Etienne P. Bernard , Werner Krauth

We provide a pedagogical introduction to the two main variants of real-space quantum Monte Carlo methods for electronic-structure calculations: variational Monte Carlo (VMC) and diffusion Monte Carlo (DMC). Assuming no prior knowledge on…

化学物理 · 物理学 2015-08-13 Julien Toulouse , Roland Assaraf , C. J. Umrigar

Diffusion Monte Carlo (DMC) based on fixed-node approximation has enjoyed significant developments in the past decades and become one of the go-to methods when accurate ground state energy of molecules and materials is needed. The remaining…

化学物理 · 物理学 2023-08-07 Weiluo Ren , Weizhong Fu , Xiaojie Wu , Ji Chen

Hamiltonian Monte Carlo (HMC) has been widely adopted in the statistics community because of its ability to sample high-dimensional distributions much more efficiently than other Metropolis-based methods. Despite this, HMC often performs…

统计计算 · 统计学 2019-11-19 Arya A. Pourzanjani , Linda R. Petzold

We develop a formalism and present an algorithm for optimization of the trial wave-function used in fixed-node diffusion quantum Monte Carlo (DMC) methods. We take advantage of a basic property of the walker configuration distribution…

强关联电子 · 物理学 2015-05-13 Fernando A. Reboredo , Randolph Q. Hood , Paul R. C. Kent

We propose a new framework for Hamiltonian Monte Carlo (HMC) on truncated probability distributions with smooth underlying density functions. Traditional HMC requires computing the gradient of potential function associated with the target…

机器学习 · 统计学 2017-09-12 Kexin Yi , Finale Doshi-Velez

Computational codes based on the Diffusion Monte Carlo method can be used to determine the quantum state of two-electron systems confined by external potentials of various nature and geometry. In this work, we show how the application of…

化学物理 · 物理学 2021-02-24 Gaia Micca Longo , Carla Maria Coppola , Domenico Giordano , Savino Longo

Adaptive Monte Carlo methods are very efficient techniques designed to tune simulation estimators on-line. In this work, we present an alternative to stochastic approximation to tune the optimal change of measure in the context of…

概率论 · 数学 2009-10-23 Benjamin Jourdain , Jérôme Lelong

We investigate the inclusion of variable spins in electronic structure quantum Monte Carlo, with a focus on diffusion Monte Carlo with Hamiltonians that include spin-orbit interactions. Following our previous introduction of fixed-phase…

计算物理 · 物理学 2016-07-27 Cody A. Melton , M. Chandler Bennett , Lubos Mitas

We obtain non asymptotic concentration bounds for two kinds of stochastic approximations. We first consider the deviations between the expectation of a given function of the Euler scheme of some diffusion process at a fixed deterministic…

概率论 · 数学 2012-12-12 Noufel Frikha , Stephane Menozzi

This topical review describes the methodology of continuum variational and diffusion quantum Monte Carlo calculations. These stochastic methods are based on many-body wave functions and are capable of achieving very high accuracy. The…

材料科学 · 物理学 2010-02-11 R. J. Needs , M. D. Towler , N. D. Drummond , P. Lopez Rios

Sequential Monte Carlo methods, also known as particle methods, are a popular set of techniques for approximating high-dimensional probability distributions and their normalizing constants. These methods have found numerous applications in…

统计计算 · 统计学 2021-06-23 Jeremy Heng , Adrian N. Bishop , George Deligiannidis , Arnaud Doucet

A local embedding and effective downfolding scheme has been developed and implemented in the auxiliary-field quantum Monte Carlo (AFQMC) method. A local cluster in which electrons are fully correlated is defined and the frozen orbital…

强关联电子 · 物理学 2019-07-24 Brandon Eskridge , Henry Krakauer , Shiwei Zhang

While Diffusion Monte Carlo (DMC) is in principle an exact stochastic method for \textit{ab initio} electronic structure calculations, in practice the fermionic sign problem necessitates the use of the fixed-node approximation and trial…

In this paper, we present a sparse grid-based Monte Carlo method for solving high-dimensional semi-linear nonlocal diffusion equations with volume constraints. The nonlocal model is governed by a class of semi-linear partial…

数值分析 · 数学 2025-07-08 Changtao Sheng , Bihao Su , Chenglong Xu

In this work we develop tools that enable the study of non-adiabatic effects with variational and diffusion Monte Carlo methods. We introduce a highly accurate wave function ansatz for electron-ion systems that can involve a combination of…

化学物理 · 物理学 2014-10-29 Norm M. Tubman , Ilkka Kylänpää , Sharon Hammes-Schiffer , David M. Ceperley

In this work, we examine sampling problems with non-smooth potentials. We propose a novel Markov chain Monte Carlo algorithm for sampling from non-smooth potentials. We provide a non-asymptotical analysis of our algorithm and establish a…

机器学习 · 计算机科学 2022-02-11 Jiaming Liang , Yongxin Chen

Diffusion generative models have excelled at diverse image generation and reconstruction tasks across fields. A less explored avenue is their application to discriminative tasks involving regression or classification problems. The…

宇宙学与河外天体物理 · 物理学 2025-02-26 Nayantara Mudur , Carolina Cuesta-Lazaro , Douglas P. Finkbeiner