  We investigate the structure of the potential energy surfaces of the
superheavy nuclei 258Fm, 264Hs, (Z=112,N=166), (Z=114,N=184), and (Z=120,N=172)
within the framework of self-consistent nuclear models, i.e. the
Skyrme-Hartree-Fock approach and the relativistic mean-field model. We compare
results obtained with one representative parametrisation of each model which is
successful in describing superheavy nuclei. We find systematic changes as
compared to the potential energy surfaces of heavy nuclei in the uranium
region: there is no sufficiently stable fission isomer any more, the importance
of triaxial configurations to lower the first barrier fades away, and
asymmetric fission paths compete down to rather small deformation. Comparing
the two models, it turns out that the relativistic mean-field model gives
generally smaller fission barriers.
