  We study suspensions of colloidal spheres with a constant zeta-potential
within Poisson-Boltzmann theory, quantifying the discharging of the spheres
with increasing colloid density and decreasing salt concentration. We use the
calculated renormalized charge of the colloids to determine their pairwise
effective screened-Coulomb repulsions. Bulk phase diagrams in the colloid
concentration-salt concentration representation follow, for various
zeta-potentials, by a mapping onto published fits of phase boundaries of
point-Yukawa systems. Although the resulting phase diagrams do feature
face-centered cubic (fcc) and body-centered cubic (bcc) phases, they are
dominated by the (re-entrant) fluid phase due to the colloidal discharging with
increasing colloid concentration and decreasing salt concentration.
