  Results are presented for simulations of electron-positron pair production in
relativistic heavy-ion collisions leading to electron capture and positron
ejection. We apply a two-center relativistic continuum distorted-wave model to
represent the electron/positron dynamics during the collision process. The
results are compared with experimental cross-section data for ${\rm La}^{57+}$
and ${\rm Au}^{79+}$ impact on Gold, Silver and Copper targets. The theory is
in very good agreement with experiment, verifying the result that the process
increases in importance with both collision energy and target atomic number,
and improves upon previous simulations of this process.
