  Molecular dynamics (MD) simulations are used to determine the diffusion
coefficients, electrophoretic mobilities and electrical conductivity of a
charged colloidal suspension in the salt-free regime as a function of the
colloid charge. The behavior of the colloidal particles' diffusion constant can
be well understood in terms of two coupled effects: counterion 'condensation'
and slowdown due to the relaxation effect. We find that the conductivity
exhibits a maximum which approximately separates the regimes of
counterion-dominated and colloid-dominated conduction. We analyze the
electrophoretic mobilities and the conductivity in terms of commonly employed
assumptions about the role of "free" and "condensed" counterions, and discuss
different interpretations of this approach.
