A new method for calculating the symmetry-projected energy of coupled-cluster singles and doubles (CCSD) wave function through the Monte Carlo method is proposed. We present benchmark calculations in considering the three-level Lipkin model which is a simple and minimal model with two phases: spherical and deformed ones. It is demonstrated that this new method gives good ground state energy and low-lying spectra.
@article{arxiv.2103.00120,
title = {Symmetry projection to coupled-cluster singles and doubles wave function through the Monte Carlo method},
author = {Takahiro Mizusaki and Peter Schuck},
journal= {arXiv preprint arXiv:2103.00120},
year = {2021}
}