  We investigate the lattice Coulomb glass model in three dimensions via Monte
Carlo simulations. No evidence for an equilibrium glass phase is found down to
very low temperatures, although the correlation length increases rapidly near
T=0. A charge-ordered phase (COP) exists at low disorder. The transition to
this phase is consistent with the Random Field Ising universality class, which
shows that the interaction is effectively screened at moderate temperature. For
large disorder, the single-particle density of states near the Coulomb gap
satisfies the scaling relation g(e,T)=T^\delta f(|e|/T) with \delta = 2.01 +/-
0.05 in agreement with the prediction of Efros and Shklovskii. For decreasing
disorder, a crossover to a larger effective exponent occurs due to the
proximity of the COP.
