Operator overlaps in harmonic oscillator bases with different oscillator lengths

A recently developed formalism is used to carry out generator coordinate method calculations using a set of Hartree-Fock-Bogoliubov wave functions, where each of the members of the set can be expanded in an arbitrary basis. In this paper it is assumed that the HFB wave functions are expanded in harmonic oscillator (HO) bases with different oscillator lengths. General expressions to compute the required matrix elements of arbitrary operators are given. The application of the present formalism to the case of fission is illustrated with an exampl