Electrostatically Embedded Many-Body Correlation Energy, with Applications to the Calculation of Accurate Second-Order Møller−Plesset Perturbation Theory Energies for Large Water Clusters

Citations Over TimeTop 10% of 2007 papers

Abstract

The electrostatically embedded many-body expansion (EE-MB), previously applied to the total electronic energy, is here applied only to the electronic correlation energy (CE), combined with a Hartree-Fock calculation on the entire system. The separate treatment of the Hartree-Fock and correlation energies provides an efficient way to approximate correlation energy for extended systems. We illustrate this here by calculating accurate Møller-Plesset second-order perturbation theory (MP2) energies for a series of clusters ranging in size from 5 to 20 water molecules. In this new method, called EE-MB-CE, where MB is pairwise additive (PA) or three-body (3B), the full Hartree-Fock energy of a system of N monomers is calculated (i.e., the many-body expansion is carried out to the Nth order), while the EE-MB method is used to calculate the correlation energy of the system. We find that not only does this new method lead to better energetics than the original EE-MB method but also that one is able to obtain excellent agreement with full MP2 calculations by considering only a two-body expansion of the correlation energy, leading to a considerable savings in computational time as compared to the three-body expansion. Additionally, we propose the use of a cutoff to further reduce the number of two-body terms that must be calculated, and we show that if a cutoff of 6 Å is used, then one can eliminate up to 44% of the pairs and still calculate energies to within 0.1% of the net interaction energy of the full cluster.

Related Papers

• → An ab initio study of model SN2 reactions with inclusion of electron correlation effects through second-order Moeller-Plesset perturbation calculations(1990)63 cited
• → Correlated one-body potential from second-order Møller-Plesset perturbation theory: Alternative to orbital-optimized MP2 method(2013)15 cited
• → Corrections to correlations energies beyond fourth order moller-plesset (MP4) perturbation theory. Contributions of single, double, and triple substitutions(1988)21 cited
• → Isoelectronic changes in total Hartree-Fock energy of atoms(1980)1 cited
• Tuning the correlation energy in second-order M{\o}ller-Plesset perturbation theory with an effective electron-electron interaction potential(2012)