Padé-resummed fourth-order many-body perturbation theory: Applications to the description of Au-Au, Au-Hg, and Hg-Hg bonds

► Padé approximants successfully resum MP4 for the system composed of Au and Hg atoms. ► Resummation of differential correlation energy expansions is recommended. ► Padé resummation improves the accuracy of composite schemes involving MP4.