We discuss the implementation of the nuclear model based on realistic nuclear
spectral functions in the GENIE neutrino interaction generator. Besides
improving on the Fermi gas description of the nuclear ground state, our scheme
involves a new prescription for Q2 selection, meant to efficiently enforce
energy momentum conservation. The results of our simulations, validated through
comparison to electron scattering data, have been obtained for a variety of
target nuclei, ranging from carbon to argon, and cover the kinematical region
in which quasi elastic scattering is the dominant reaction mechanism. We also
analyse the influence of the adopted nuclear model on the determination of
neutrino oscillation parameters.Comment: 19 pages, 35 figures, version accepted by Phys. Rev.