  We show that describing the screened electrostatic interactions in a periodic
stack of rigid parallel identical charged plate-like colloids within a local
density functional theory approach, generically leads to a swelling behaviour.
Within the same framework, we find that the effective potential between a pair
of such plates immersed in an electrolyte is repulsive at all distances. This
general result is in contradiction with a theory put forward by Sogami,
Shinohara and Smalley, that we criticize and thoroughly reconsider to show how
the two approaches can be reconciled.
