  A shape change of the self-consistent mean-field induced by a configuration
change is discussed within the conventional constrained Hartree-Fock (CHF)
theory. It is stressed that a single-particle level crossing dynamics should be
treated carefully, because the shape of the mean-field in such a finite
many-body system as the nucleus strongly changes depending on its
configuration. This situation is clearly shown by applying an adiabatic
assumption, where the most energetically favorable single-particle states are
assumed to be occupied. The excited HF states and the continuously-connected
potential energy curves are given by applying the configuration dictated CHF
method. The effect of pairing correlation is discussed in the level crossing
region. Triaxial deformed results in our Hartree-Fock-Bogoliubov (HFB)
calculation with Gogny force nicely reproduce the available experimental data
of Ge isotopes. From our numerical calculation, it is concluded that the CHFB
state is more fragile than the CHF state in the level crossing region.
