We propose a pseudopotential for the electron-electron Coulomb interaction to
improve the efficiency of many-body electronic structure calculations. The
pseudopotential accurately replicates the scattering properties of the Coulomb
interaction, and recovers the analytical solution for two electrons in a
parabolic trap. A case study for the homogeneous electron gas using the
diffusion Monte Carlo and configuration interaction methods recovers highly
accurate values for the ground state energy, and the smoother potential reduces
the computational cost by a factor of ~30. Finally, we demonstrate the use of
the pseudopotential to study isolated lithium and beryllium atoms.GJC acknowledges the financial support of the Royal Society and Gonville & Caius College.This is the author accepted manuscript. The final version is available from APS via http://dx.doi.org/http://dx.doi.org/10.1103/PhysRevB.92.07510
