  The eigenstates and the scattering transmission for two interacting electrons
are found exactly for I quantum dots, including the hybridization with the
states on the leads. The results imply limitations on the validity of the
Coulomb blockade picture. The ground states for I=1, and 2 on a
one--dimensional chain (modeling single and double quantum dots) exhibit
quantum delocalization and magnetic transitions. The effective transmission T
of two interacting electrons through one impurity (I=1) is enhanced by a
renormalization of the repulsive interaction, when one of the electrons is
captured in a strongly localized state.
