scholarly journals CAP-EOM-CCSD Method with Smooth Voronoi CAP for Metastable Electronic States in Molecular Clusters

2020 ◽  
Author(s):  
James Gayvert ◽  
Ksenia Bravaya
Keyword(s):  
Molecular Species ◽  
Electronic States ◽  
Equation Of Motion ◽  
Molecular Clusters ◽  
Metastable States ◽  
Coupled Cluster ◽  
Vacuum Region ◽  
Practical Tool ◽  
Ccsd Method

The complex absorbing potential (CAP) approach offers a practical tool for characterization of energies and lifetimes of metastable electronic states, such as temporary anions and core ionized states. Here, we present an implementation of the smooth Voronoi CAP combined with equation-of-motion coupled cluster with single and double substitutions method for metastable states. The performance of the smooth Voronoi and a standard box CAPs is compared for different classes of systems: resonances in isolated molecules and in molecular clusters. The results of the benchmark calculations indicate that the choice of the CAP shape should be guided by the character of the metastable states. While Voronoi CAPs yield stable results in the case of a resonance localized on one molecule, their performance in the cases of states delocalized over two or more molecular species can deteriorate due to the CAP leaking into the vacuum region between the moieties. <br>

scholarly journals CAP-EOM-CCSD Method with Smooth Voronoi CAP for Metastable Electronic States in Molecular Clusters

2020 ◽  
Author(s):  
James Gayvert ◽  
Ksenia Bravaya
Keyword(s):  
Molecular Species ◽  
Electronic States ◽  
Equation Of Motion ◽  
Molecular Clusters ◽  
Metastable States ◽  
Coupled Cluster ◽  
Vacuum Region ◽  
Practical Tool ◽  
Ccsd Method

The complex absorbing potential (CAP) approach offers a practical tool for characterization of energies and lifetimes of metastable electronic states, such as temporary anions and core ionized states. Here, we present an implementation of the smooth Voronoi CAP combined with equation-of-motion coupled cluster with single and double substitutions method for metastable states. The performance of the smooth Voronoi and a standard box CAPs is compared for different classes of systems: resonances in isolated molecules and in molecular clusters. The results of the benchmark calculations indicate that the choice of the CAP shape should be guided by the character of the metastable states. While Voronoi CAPs yield stable results in the case of a resonance localized on one molecule, their performance in the cases of states delocalized over two or more molecular species can deteriorate due to the CAP leaking into the vacuum region between the moieties. <br>

scholarly journals Dyson Orbitals within the fc-CVS-EOM-CCSD Framework

2019 ◽  
Author(s):  
Marta L. Vidal ◽  
Anna Krylov ◽  
Sonia Coriani
Keyword(s):  
Excited States ◽  
Cross Sections ◽  
Ground State ◽  
Equation Of Motion ◽  
Photoelectron Spectra ◽  
Coupled Cluster ◽  
Time Resolved ◽  
X Ray ◽  
Ccsd Method

We report on the implementation and illustrative applications of Dyson orbitals within the recently proposed frozen-core (fc) core-valence separated (CVS) equation-of-motion (EOM) coupled-cluster singles and doubles (CCSD) method, which enables efficient and accurate characterization of core-ionized states. Dyson orbitals are reduced quantities that can be interpreted as correlated states of the ejected/attached electron.<br>Dyson orbitals enter the expressions of various experimental observables, such as photoionization cross sections; thus, they are necessary for modeling photoelectron spectra.<br>Here we discuss the simulations of X-ray photoelectron spectra (XPS) and propose an approach to simulate time-resolved (TR-)XPS for probing excited states. <br>As illustrative examples, we present the simulation of the XPS of the ground state of adenine and of TR-XPS of the excited states of uracil.

Application of equation-of-motion coupled-cluster methods to low-lying singlet and triplet electronic states of HBO and BOH

2005 ◽  
Vol 122 (23) ◽  
pp. 234316 ◽  
Author(s):  
Nathan J. DeYonker ◽  
Se Li ◽  
Yukio Yamaguchi ◽  
Henry F. Schaefer ◽  
T. Daniel Crawford ◽  
...  
Keyword(s):  
Electronic States ◽  
Equation Of Motion ◽  
Coupled Cluster ◽  
Coupled Cluster Methods ◽  
Cluster Methods

scholarly journals Dyson Orbitals within the fc-CVS-EOM-CCSD Framework: Theory and Application to X-ray Photoelectron Spectroscopy of Ground and Excited States

2019 ◽  
Author(s):  
Marta L. Vidal ◽  
Anna Krylov ◽  
Sonia Coriani
Keyword(s):  
Excited States ◽  
Ground State ◽  
Photoelectron Spectroscopy ◽  
Equation Of Motion ◽  
Photoelectron Spectra ◽  
Coupled Cluster ◽  
Time Resolved ◽  
X Ray ◽  
Target States

We report on the implementation of Dyson orbitals within the recently introduced frozen-core (fc) core-valence separated (CVS) equation-of-motion (EOM) coupled-cluster singles and doubles (CCSD) method, which enables efficient and reliable characterization of core-level states. The ionization potential (IP) variant of fc-CVS-EOM-CCSD, in which the EOM target states have one electron less than the reference, gives access to core-ionized states thus enabling modeling of<br><div>X-ray photoelectron spectra (XPS) and its time-resolved variant (TR-XPS). Dyson orbitals are reduced quantities that can be interpreted as correlated states of the ejected/attached electron; they enter the expressions of various experimentally relevant quantities. In the context of photoelectron spectroscopy, Dyson orbitals can be used to estimate the strengths of photoionization transitions. We illustrate the utility of Dyson orbitals and fc-CVS-EOM-IP-CCSD by calculating XPS of the ground state of adenine and TR-XPS of the excited states of uracil.</div>

scholarly journals Dyson Orbitals within the fc-CVS-EOM-CCSD Framework: Theory and Application to X-ray Photoelectron Spectroscopy of Ground and Excited States

2019 ◽  
Author(s):  
Marta L. Vidal ◽  
Anna Krylov ◽  
Sonia Coriani
Keyword(s):  
Excited States ◽  
Ground State ◽  
Photoelectron Spectroscopy ◽  
Equation Of Motion ◽  
Photoelectron Spectra ◽  
Coupled Cluster ◽  
Time Resolved ◽  
X Ray ◽  
Target States

We report on the implementation of Dyson orbitals within the recently introduced frozen-core (fc) core-valence separated (CVS) equation-of-motion (EOM) coupled-cluster singles and doubles (CCSD) method, which enables efficient and reliable characterization of core-level states. The ionization potential (IP) variant of fc-CVS-EOM-CCSD, in which the EOM target states have one electron less than the reference, gives access to core-ionized states thus enabling modeling of<br><div>X-ray photoelectron spectra (XPS) and its time-resolved variant (TR-XPS). Dyson orbitals are reduced quantities that can be interpreted as correlated states of the ejected/attached electron; they enter the expressions of various experimentally relevant quantities. In the context of photoelectron spectroscopy, Dyson orbitals can be used to estimate the strengths of photoionization transitions. We illustrate the utility of Dyson orbitals and fc-CVS-EOM-IP-CCSD by calculating XPS of the ground state of adenine and TR-XPS of the excited states of uracil.</div>

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