Development of Theoretical Tools for ...
Document type :
Autre communication scientifique (congrès sans actes - poster - séminaire...)
Title :
Development of Theoretical Tools for Modeling Core and Valence Spectroscopies and their Applications to Species of Atmospheric Interest
Author(s) :
Halbert, Loïc [Orateur]
Physico-Chimie Moléculaire Théorique [PCMT]
López Vidal, Marta [Auteur]
Danmarks Tekniske Universitet = Technical University of Denmark [DTU]
Shee, Avijit [Auteur]
Department of Chemistry [Ann Arbor]
Coriani, Sonia [Auteur]
Danmarks Tekniske Universitet = Technical University of Denmark [DTU]
Severo Pereira Gomes, Andre [Auteur]
Physico-Chimie Moléculaire Théorique [PCMT]
Physico-Chimie Moléculaire Théorique [PCMT]
López Vidal, Marta [Auteur]
Danmarks Tekniske Universitet = Technical University of Denmark [DTU]
Shee, Avijit [Auteur]
Department of Chemistry [Ann Arbor]
Coriani, Sonia [Auteur]
Danmarks Tekniske Universitet = Technical University of Denmark [DTU]
Severo Pereira Gomes, Andre [Auteur]
Physico-Chimie Moléculaire Théorique [PCMT]
Conference title :
JTMS 2020 : Journées "Théorie, Modélisation et Simulation"
City :
Visioconférence
Country :
France
Start date of the conference :
2020-11-02
Publication date :
2020-11-02
HAL domain(s) :
Chimie/Chimie théorique et/ou physique
Physique [physics]/Physique [physics]/Chimie-Physique [physics.chem-ph]
Physique [physics]/Physique [physics]/Chimie-Physique [physics.chem-ph]
English abstract : [en]
Achieving the ionization potentials of core electrons is becoming easier with the advances in X-ray spectroscopy, both the high energies become accessible and the precision improves [1]. The consideration of relativistic ...
Show more >Achieving the ionization potentials of core electrons is becoming easier with the advances in X-ray spectroscopy, both the high energies become accessible and the precision improves [1]. The consideration of relativistic effects is necessary [2], so we are working to obtain these energies using 4-component Hamiltonians (Dirac-Coulomb / Dirac-Coulomb-Gaunt) by Equation of Motion Coupled Cluster (EOM-CCSD) implemented in the DIRAC code [3]. This method has many advantages both in terms of its precision and its predictions [4]. The size of the matrix (EOM) and the computational cost in N , real computational limitations, can be outwitted by the use of approximations, namely when calculating the reference wavefunction by neglecting some amplitudes T of the CC calculation (Frozen-Core (FC) [3]), or by limiting its size by the use of projectors (Core Valence Separation (CVS) [5,6] / No Double Excitation in Core (ND) [3]). This work shows the interest of applying these approximations and of testing their different degrees of precision in order to obtain the ionization energies of the core electrons. The studied systems are notably the highly relativistic core electrons in Xe, and {X<sup>-</sup>; HX (with X in {Cl, Br, I}) which have atmospheric interests.<br><br>[1] Boudjemia N. et al., Phys. Chem. Chem. Phys. 21, 5448, (2019)<br>[2] Fleig T. et al., Chem. Phys. 2 395 (2012); Saue T. et al., Chem. Phys. Chem. 12 3077, (2011)<br>[3] Saue T. et al, J. Chem. Phys. 152; 204104, (2020)<br>[4] Shee A. et al., J. Chem. Phys. 149, 174113, (2018)<br>[5] Coriani S. et al., J. Chem. Phys 143, 181103, (2015)<br>[6] Dreuw, A. et al., WIREs Comp. Mol S, 5:82-95, (2015)<br>[7] Southworth S. H. et al., J. Chem. Phys, 142, 224302, (2015)<br>[8] Oura M. et al. New J. Phys 21, 043015, (2019)<br>[9] Sikkema J. et al.,J. Chem. Phys. 131, 124116 (2009)<br>Show less >
Show more >Achieving the ionization potentials of core electrons is becoming easier with the advances in X-ray spectroscopy, both the high energies become accessible and the precision improves [1]. The consideration of relativistic effects is necessary [2], so we are working to obtain these energies using 4-component Hamiltonians (Dirac-Coulomb / Dirac-Coulomb-Gaunt) by Equation of Motion Coupled Cluster (EOM-CCSD) implemented in the DIRAC code [3]. This method has many advantages both in terms of its precision and its predictions [4]. The size of the matrix (EOM) and the computational cost in N , real computational limitations, can be outwitted by the use of approximations, namely when calculating the reference wavefunction by neglecting some amplitudes T of the CC calculation (Frozen-Core (FC) [3]), or by limiting its size by the use of projectors (Core Valence Separation (CVS) [5,6] / No Double Excitation in Core (ND) [3]). This work shows the interest of applying these approximations and of testing their different degrees of precision in order to obtain the ionization energies of the core electrons. The studied systems are notably the highly relativistic core electrons in Xe, and {X<sup>-</sup>; HX (with X in {Cl, Br, I}) which have atmospheric interests.<br><br>[1] Boudjemia N. et al., Phys. Chem. Chem. Phys. 21, 5448, (2019)<br>[2] Fleig T. et al., Chem. Phys. 2 395 (2012); Saue T. et al., Chem. Phys. Chem. 12 3077, (2011)<br>[3] Saue T. et al, J. Chem. Phys. 152; 204104, (2020)<br>[4] Shee A. et al., J. Chem. Phys. 149, 174113, (2018)<br>[5] Coriani S. et al., J. Chem. Phys 143, 181103, (2015)<br>[6] Dreuw, A. et al., WIREs Comp. Mol S, 5:82-95, (2015)<br>[7] Southworth S. H. et al., J. Chem. Phys, 142, 224302, (2015)<br>[8] Oura M. et al. New J. Phys 21, 043015, (2019)<br>[9] Sikkema J. et al.,J. Chem. Phys. 131, 124116 (2009)<br>Show less >
Language :
Anglais
Peer reviewed article :
Oui
Audience :
Internationale
Popular science :
Non
ANR Project :
Source :