Abstract
We develop a method based on equation-of-motion coupled-cluster theory to describe properties of open-shell nuclei with nucleons outside a closed shell. We perform proof-of-principle calculations for the ground states of the helium isotopes and the first excited state in . The comparison with exact results from matrix diagonalization in small model spaces demonstrates the accuracy of the coupled-cluster methods. Three-particle–one-hole excitations of play an important role for the accurate description of . For the open-shell nucleus , the computational cost of the method is comparable with the coupled-cluster singles-and-doubles approximation while its accuracy is similar to the coupled-cluster with singles, doubles, and triples excitations.
- Received 8 February 2011
DOI:https://doi.org/10.1103/PhysRevC.83.054306
©2011 American Physical Society