We construct a pseudopotential form factor and a metallic interionic potential using Shaw's nonlocal model potential and the many-electron screening due to Singwi et al. for eight simple metals. We have particularly examined the role of many-electron effects and found them to contribute significantly to the pseudopotential form factor in the region of kF<q<2.2kF and to be essential in determining a realistic interionic potential. In addition, we have studied the effects of exchange and correlation on the residual resistivity due to vacancies, the resistivity of liquid metals, the interatomic force constants, and the sound velocity. The inclusion of many-electron effects invariably improves the agreement between theory and experiment.