T. Otsuka et al., STRUCTURE OF THE N = Z = 28 CLOSED-SHELL STUDIED BY MONTE-CARLO SHELL-MODEL CALCULATION, Physical review letters, 81(8), 1998, pp. 1588-1591
The closed shell structure at N = Z = 28 is studied by a large-scale s
hell model calculation by the quantum Monte Carlo diagonalization meth
od. Latest crucial improvements of the method are described. The doubl
y closed shell probability of Ni-56 is shown to be only (49)% in a ful
l pf shell calculation, in contrast to the corresponding probability o
f Ca-48 which reaches 86%.