The performance of approximate equation ...
Document type :
Compte-rendu et recension critique d'ouvrage
Title :
The performance of approximate equation of motion coupled cluster for valence and core states of heavy element systems
Author(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]

Physico-Chimie Moléculaire Théorique [PCMT]
Journal title :
Molecular Physics
Publisher :
Taylor & Francis
Publication date :
2023-08-18
ISSN :
0026-8976
HAL domain(s) :
Chimie/Chimie théorique et/ou physique
English abstract : [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 ...
Show more >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.Show less >
Show more >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.Show less >
Language :
Anglais
Popular science :
Non
ANR Project :
Comment :
5 figures, 4 tables
Source :
Files
- 2307.01342
- Open access
- Access the document