0000000000563849
AUTHOR
Rolf H. Myhre
showing 3 related works from this author
The Dalton quantum chemistry program system
2013
Dalton is a powerful general-purpose program system for the study of molecular electronic structure at the Hartree-Fock, Kohn-Sham, multiconfigurational self-consistent-field, MOller-Plesset, confi ...
Multi-level coupled cluster theory
2014
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 prese…
The extended CC2 model ECC2
2013
We present a size-extensive extension to the CC2 model that avoids the complications with quasi-degeneracies that are present in the CC2 model and related perturbation theory-based approaches. The formulation also provides a consistent model for treating different parts of a molecular system at different levels of electron correlation. Such a subsystem approach leads to large reductions in the computational requirements without compromising the accuracy. In this initial study, we focus on static molecular properties. © 2013 Copyright Taylor and Francis Group, LLC.