The performance of approximate equation ...
Type de document :
Compte-rendu et recension critique d'ouvrage
Titre :
The performance of approximate equation of motion coupled cluster for valence and core states of heavy element systems
Auteur(s) :
Halbert, Loïc [Auteur]
Physico-Chimie Moléculaire Théorique [PCMT]
Severo Pereira Gomes, Andre [Auteur]
Physico-Chimie Moléculaire Théorique [PCMT]
Physico-Chimie Moléculaire Théorique [PCMT]
Severo Pereira Gomes, Andre [Auteur]
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Physico-Chimie Moléculaire Théorique [PCMT]
Titre de la revue :
Molecular Physics
Éditeur :
Taylor & Francis
Date de publication :
2023-08-18
ISSN :
0026-8976
Discipline(s) HAL :
Chimie/Chimie théorique et/ou physique
Résumé en anglais : [en]
The equation of motion coupled cluster singles and doubles model (EOM-CCSD) is an accurate, black-box correlated electronic structure approach to investigate electronically excited states and electron attachment or detachment ...
Lire la suite >The equation of motion coupled cluster singles and doubles model (EOM-CCSD) is an accurate, black-box correlated electronic structure approach to investigate electronically excited states and electron attachment or detachment processes. It has also served as a basis for developing less computationally expensive approximate models such as partitioned EOM-CCSD (P-EOM-CCSD), the second-order many-body perturbation theory EOM (EOM-MBPT(2)), and their combination (P-EOM-MBPT(2)) [S. Gwaltney et al., Chem. Phys. Lett. <b>248</b>, 189-198 (1996)]. In this work we outline an implementation of these approximations for four-component based Hamiltonians and investigate their accuracy relative to EOM-CCSD for valence excitations, valence and core ionizations and electron attachment, and this for a number of systems of atmospheric or astrophysical interest containing elements across the periodic table. We have found that across the different systems and electronic states of different nature considered, partition EOM-CCSD yields results with the largest deviations from the reference, whereas second-order based approaches tend show a generally better agreement with EOM-CCSD. We trace this behavior to the imbalance brought about by the removal of excited state relaxation in the partition approaches, with respect to degree of electron correlation recovered.Lire moins >
Lire la suite >The equation of motion coupled cluster singles and doubles model (EOM-CCSD) is an accurate, black-box correlated electronic structure approach to investigate electronically excited states and electron attachment or detachment processes. It has also served as a basis for developing less computationally expensive approximate models such as partitioned EOM-CCSD (P-EOM-CCSD), the second-order many-body perturbation theory EOM (EOM-MBPT(2)), and their combination (P-EOM-MBPT(2)) [S. Gwaltney et al., Chem. Phys. Lett. <b>248</b>, 189-198 (1996)]. In this work we outline an implementation of these approximations for four-component based Hamiltonians and investigate their accuracy relative to EOM-CCSD for valence excitations, valence and core ionizations and electron attachment, and this for a number of systems of atmospheric or astrophysical interest containing elements across the periodic table. We have found that across the different systems and electronic states of different nature considered, partition EOM-CCSD yields results with the largest deviations from the reference, whereas second-order based approaches tend show a generally better agreement with EOM-CCSD. We trace this behavior to the imbalance brought about by the removal of excited state relaxation in the partition approaches, with respect to degree of electron correlation recovered.Lire moins >
Langue :
Anglais
Vulgarisation :
Non
Projet ANR :
Commentaire :
5 figures, 4 tables
Source :
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