  A 3D-dynamical model is constructed for the study of motion in the central
regions of a disk galaxy with a double nucleus. Using the results of the
2D-model, we find the regions of initial conditions in the (x,px,z,py)=EJ,
(y=pz=0) phase space producing regular or chaotic orbits. The majority of stars
are on chaotic orbits. All chaotic orbits come arbitrary close to one or to
both nuclei. Regular orbits are those starting near the stable periodic orbits
of the 2D-system with small values of z0. All regular orbits circulate around
only one of the two nuclei.
