A modified Jellium model, which includes the lattice effects in the form of Ashcroft pseudopotential, is analyzed using Smith＇s one-parameter family of trial function for electron-density profile, and work functions are calculated for various single crystals at the metal/vacuum interface. Face-dependent potential of zero charge (PZC) values for five sp metals are obtained by coupling the monolayer model of solvent dipoles with the modified Jellium model for the metal. The solvent molecules at the metal/solution interface are assigned two orientational states, and the dipolar interactions are treated using the Bethe approximation. A method of obtaining the work function, PZC, and surface potential for polycrystalline samples by suitably averaging over the single-crystal planes is outlined.