How to renormalize coupled cluster theory

Abstract

Coupled cluster theory is an attractive tool to solve the quantum many-body problem because its singles and doubles (CCSD) approximation is computationally affordable and yields about 90% of the correlation energy. Capturing the remaining 10%, e.g. via including triples, is numerically expensive. Here we assume that short-range three-body correlations dominate and - following Lepage [How to renormalize the Schrödinger equation, arXiv:nucl-th/9706029] - that their effects can be included within CCSD by renormalizing the three-body contact interaction. We renormalize this contact in ${}^{16}$O and obtain accurate CCSD results for ${}^{24}$O, ${}^{20-34}$Ne, ${}^{40,48}$Ca, ${}^{78}$Ni, ${}^{90}$Zr, and ${}^{100}$Sn.

Comments: 7 pages, 4 figures