  Static self-consistent methods usually allow to determine the most probable
fission fragments mass asymmetry. We have applied random neck rupture mechanism
to the nuclei in the configuration at the end of fission paths. Fission
fragment mass distributions have been deduced from the pre-scission nuclear
density distribution obtained from the self-consistent calculations. Potential
energy surfaces as well as nuclear shapes have been calculated in the fully
microscopic theory, namely the constrained Hartree-Fock-Bogolubov model with
the effective Gogny D1S density-dependent interaction. The method has been
applied for analysis of fission of Fm-256,258, Cf-252 and Hg-180 and compared
with the experimental data.
