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RESEARCH PRODUCT

Multi-level coupled cluster theory

Alfredo Sánchez De MerásHenrik KochHenrik KochRolf H. MyhreRolf H. Myhre

subject

Density matrixElectronic correlationChemistryHartree–Fock methodGeneral Physics and AstronomyClassification of discontinuitiesPhysics and Astronomy (all)symbols.namesakeCoupled clusterPauli exclusion principleQuantum mechanicssymbolsStatistical physicsPhysical and Theoretical ChemistryWave functionCholesky decomposition

description

We present a general formalism where different levels of coupled cluster theory can be applied to different parts of the molecular system. The system is partitioned into subsystems by Cholesky decomposition of the one-electron Hartree-Fock density matrix. In this way the system can be divided across chemical bonds without discontinuities arising. The coupled cluster wave function is defined in terms of cluster operators for each part and these are determined from a set of coupled equations. The total wave function fulfills the Pauli-principle across all borders and levels of electron correlation. We develop the associated response theory for this multi-level coupled cluster theory and present proof of principle applications. The formalism is an essential tool in order to obtain size-intensive complexity in the calculation of local molecular properties.

yearjournalcountryeditionlanguage
2014-12-16The Journal of Chemical Physics
https://doi.org/10.1063/1.4903195