Continuum variational and diffusion quantum Monte Carlo calculations

TL;DR

This review explains continuum variational and diffusion quantum Monte Carlo methods, highlighting their high accuracy, scalability on petascale computers, and applications to many-body quantum systems.

Contribution

It provides a comprehensive overview of the methodologies, algorithms, and practical considerations for implementing quantum Monte Carlo calculations in continuum systems.

Findings

Methods achieve high accuracy in many-body wave function calculations

Algorithms are highly parallelizable and scalable to petascale computing

Guidance on system applications and calculation techniques provided

Abstract

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 algorithms are intrinsically parallel and well-suited to petascale computers, and the computational cost scales as a polynomial of the number of particles. A guide to the systems and topics which have been investigated using these methods is given. The bulk of the article is devoted to an overview of the basic quantum Monte Carlo methods, the forms and optimisation of wave functions, performing calculations within periodic boundary conditions, using pseudopotentials, excited-state calculations, sources of calculational inaccuracy, and calculating energy differences and forces.