SEARCH Articles Figures Tables Correlated electrons Correlation electron Electron correlation Mpller-Plesset perturbation theory) Electron correlation method Density-functional theory Mpller-Plesset Electron correlation methods Mpller-Plesset perturbation theory Electronic correlations Mpller Mpller-Plesset Mpller-Plesset second-order perturbation electron correlation The Mpller-Plesset Approach to Electron Correlation