A simple and efficient approach to the optimization of correlated wave functions

TL;DR

This paper introduces a simple, efficient method for optimizing correlated wave functions in quantum Monte Carlo calculations, improving accuracy by iteratively refining the wave function through an effective Hamiltonian approach.

Contribution

The paper presents a novel perturbative optimization method for the determinantal component of wave functions, enhancing quantum Monte Carlo accuracy with fewer computational resources.

Findings

Successfully optimized parameters for acetone's ground state

Improved accuracy for the $1{}^1{B}_{1u}$ state of hexatriene

Demonstrated efficiency and effectiveness of the method

Abstract

We present a simple and efficient method to optimize within energy minimization the determinantal component of the many-body wave functions commonly used in quantum Monte Carlo calculations. The approach obtains the optimal wave function as an approximate perturbative solution of an effective Hamiltonian iteratively constructed via Monte Carlo sampling. The effectiveness of the method as well as its ability to substantially improve the accuracy of quantum Monte Carlo calculations is demonstrated by optimizing a large number of parameters for the ground state of acetone and the difficult case of the $1{}^1{B}_{1u}$ state of hexatriene.