Calculation of energy levels with the hybrid multi-determinant method in the fp region

We compare the recent exact and coupled-cluster calculations (Phys. Rev. Lett. 98, 112501 (2007)) of energy levels using the GXPF1A Hamiltonian modified with variable shell gap with the cor- responding results obtained with the hybrid multi-determinant scheme. We show that the hybrid multi- determinant scheme is highly cost-efficient and very accurate for several angular momenta and variable shell gap of the f5/2, p3/2, p1/2 shells relative to the f7/2 shell.