Chemical Physics Letters, Vol.662, 228-234, 2016
Partitioning dynamic electron correlation energy: Viewing Moller-Plesset correlation energies through Interacting Quantum Atom (IQA) energy partitioning
Here MP2, MP3 and MP4(SDQ) are energy-partitioned for the first time within the Interacting Quantum Atoms (IQA) context, as proof-of-concept for H-2, He-2 and HF. Energies are decomposed into four primary energy contributions: (i) atomic self-energies, and atomic interaction energies comprising of (ii) Coulomb, (iii) exchange and (iv) dynamic election correlation terms. We generate and partition one and two-particle density-matrices to obtain all atomic energy components. This work suggests that, in terms of Van der Waals dispersion, the correlation energies represent an atomic stabilisation, by proximity to other atoms, as opposed to direct interactions with other nearby atoms. (C) 2016 The Authors. Published by Elsevier B.V.