New variational Monte Carlo method with an energy variance extrapolation for large-scale shell-model calculations

TL;DR

This paper introduces a novel variational Monte Carlo approach with energy variance extrapolation, enabling large-scale shell-model calculations of energies and transition strengths with improved accuracy.

Contribution

It presents a new stochastic VMC method using a projected correlated pair state, Pfaffian, and MCMC, combined with energy variance extrapolation for precise shell-model energy estimates.

Findings

Accurately calculates yrast energies and electromagnetic transition strengths.

Estimates exact shell-model energies through variance extrapolation.

Demonstrates effectiveness in large-scale shell-model calculations.

Abstract

We propose a new variational Monte Carlo (VMC) method with an energy variance extrapolation for large-scale shell-model calculations. This variational Monte Carlo is a stochastic optimization method with a projected correlated condensed pair state as a trial wave function, and is formulated with the M-scheme representation of projection operators, the Pfaffian and the Markov-chain Monte Carlo (MCMC). Using this method, we can stochastically calculate approximated yrast energies and electro-magnetic transition strengths. Furthermore, by combining this VMC method with energy variance extrapolation, we can estimate exact shell-model energies.