  We study salt-induced charge overcompensation and charge inversion of
flexible polyelectrolytes via computer simulations and demonstrate the
importance of ion excluded volume. Reentrant condensation takes place when the
ion size is comparable to monomer size, and happens in a middle region of salt
concentration. In a high-salt region, ions can overcharge a chain near its
surface and charge distribution around a chain displays an oscillatory
behavior. Unambiguous evidence obtained by electrophoresis shows that charge
inversion does not necessarily appear with overcharging and occurs when the ion
size is not big. These findings suggest a disconnection of resolubilization of
polyelectrolyte condensates at high salt concentration with charge inversion.
