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Song Q, Liu B, Wu J, Zou W, Wang Y, Suo B, Lei Y. GUGA-based MRCI approach with core-valence separation approximation (CVS) for the calculation of the core-excited states of molecules. J Chem Phys 2024; 160:094114. [PMID: 38445728 DOI: 10.1063/5.0189443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 02/14/2024] [Indexed: 03/07/2024] Open
Abstract
We develop and demonstrate how to use the Graphical Unitary Group Approach (GUGA)-based MRCISD with Core-Valence Separation (CVS) approximation to compute the core-excited states. First, perform a normal Self-Consistent-Field (SCF) or valence MCSCF calculation to optimize the molecular orbitals. Second, rotate the optimized target core orbitals and append to the active space, form an extended CVS active space, and perform a CVS-MCSCF calculation for core-excited states. Finally, construct the CVS-MRCISD expansion space and perform a CVS-MRCISD calculation to optimize the CI coefficients based on the variational method. The CVS approximation with GUGA-based methods can be implemented by flexible truncation of the Distinct Row Table. Eliminating the valence-excited configurations from the CVS-MRCISD expansion space can prevent variational collapse in the Davidson iteration diagonalization. The accuracy of the CVS-MRCISD scheme was investigated for excitation energies and compared with that of the CVS-MCSCF and CVS-CASPT2 methods using the same active space. The results show that CVS-MRCISD is capable of reproducing well-matched vertical core excitation energies that are consistent with experiments by combining large basis sets and a rational reference space. The calculation results also highlight the fact that the dynamic correlation between electrons makes an undeniable contribution in core-excited states.
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Affiliation(s)
- Qi Song
- Institute of Modern Physics, Northwest University, Xi'an, Shaanxi 710069, China
| | - Baoyuan Liu
- Institute of Modern Physics, Northwest University, Xi'an, Shaanxi 710069, China
| | - Junfeng Wu
- Institute of Modern Physics, Northwest University, Xi'an, Shaanxi 710069, China
| | - Wenli Zou
- Institute of Modern Physics, Northwest University, Xi'an, Shaanxi 710069, China
| | - Yubin Wang
- Institute of Modern Physics, Northwest University, Xi'an, Shaanxi 710069, China
| | - Bingbing Suo
- Institute of Modern Physics, Northwest University, Xi'an, Shaanxi 710069, China
| | - Yibo Lei
- College of Chemistry and Materials Science, Northwest University, Xi'an, Shaanxi 710069, People's Republic of China
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2
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Leroux J, Kotobi A, Hirsch K, Lau T, Ortiz-Mahecha C, Maksimov D, Meißner R, Oostenrijk B, Rossi M, Schubert K, Timm M, Trinter F, Unger I, Zamudio-Bayer V, Schwob L, Bari S. Mapping the electronic transitions of protonation sites in peptides using soft X-ray action spectroscopy. Phys Chem Chem Phys 2023; 25:25603-25618. [PMID: 37721108 DOI: 10.1039/d3cp02524a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
Near-edge X-ray absorption mass spectrometry (NEXAMS) around the nitrogen and oxygen K-edges was employed on gas-phase peptides to probe the electronic transitions related to their protonation sites, namely at basic side chains, the N-terminus and the amide oxygen. The experimental results are supported by replica exchange molecular dynamics and density-functional theory and restricted open-shell configuration with single calculations to attribute the transitions responsible for the experimentally observed resonances. We studied five tailor-made glycine-based pentapeptides, where we identified the signature of the protonation site of N-terminal proline, histidine, lysine and arginine, at 406 eV, corresponding to N 1s → σ*(NHx+) (x = 2 or 3) transitions, depending on the peptides. We compared the spectra of pentaglycine and triglycine to evaluate the sensitivity of NEXAMS to protomers. Separate resonances have been identified to distinguish two protomers in triglycine, the protonation site at the N-terminus at 406 eV and the protonation site at the amide oxygen characterized by a transition at 403.1 eV.
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Affiliation(s)
- Juliette Leroux
- CIMAP, CEA/CNRS/ENSICAEN/Université de Caen Normandie, 14050 Caen, France
- Deutsches Elektronen-Synchrotron DESY, Germany.
| | - Amir Kotobi
- Deutsches Elektronen-Synchrotron DESY, Germany.
- Helmholtz-Zentrum Hereon, Institute of Surface Science, 21502 Geesthacht, Germany
| | - Konstantin Hirsch
- Abteilung Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, 12489 Berlin, Germany
| | - Tobias Lau
- Abteilung Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, 12489 Berlin, Germany
| | - Carlos Ortiz-Mahecha
- Hamburg University of Technology, Institute of Polymers and Composites, 21073 Hamburg, Germany
| | - Dmitrii Maksimov
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
| | - Robert Meißner
- Helmholtz-Zentrum Hereon, Institute of Surface Science, 21502 Geesthacht, Germany
- Hamburg University of Technology, Institute of Polymers and Composites, 21073 Hamburg, Germany
| | | | - Mariana Rossi
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
| | | | - Martin Timm
- Abteilung Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, 12489 Berlin, Germany
| | - Florian Trinter
- Institut für Kernphysik, Goethe-Universität Frankfurt am Main, 60438 Frankfurt am Main, Germany
- Molecular Physics, Fritz-Haber-Institut der Max-Planck-Gesellschaft, 14195 Berlin, Germany
| | - Isaak Unger
- Department of Physics and Astronomy, Uppsala University, 75120 Uppsala, Sweden
| | - Vicente Zamudio-Bayer
- Abteilung Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, 12489 Berlin, Germany
| | | | - Sadia Bari
- Deutsches Elektronen-Synchrotron DESY, Germany.
- The Hamburg Centre for Ultrafast Imaging, Hamburg, Germany
- Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands
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3
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Zheng X, Zhang C, Jin Z, Southworth SH, Cheng L. Benchmark relativistic delta-coupled-cluster calculations of K-edge core-ionization energies of third-row elements. Phys Chem Chem Phys 2022; 24:13587-13596. [PMID: 35616685 DOI: 10.1039/d2cp00993e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
A benchmark computational study of K-edge core-ionization energies of third-row elements using relativistic delta-coupled-cluster (ΔCC) methods and a revised core-valence separation (CVS) scheme is reported. High-level relativistic (HLR) corrections beyond the spin-free exact two-component theory in its one-electron variant (SFX2C-1e), including the contributions from two-electron picture-change effects, spin-orbit coupling, the Breit term, and quantum electrodynamics effects, have been taken into account and demonstrated to play an important role. Relativistic ΔCC calculations are shown to provide accurate results for core-ionization energies of third-row elements. The SFX2C-1e-CVS-ΔCC results augmented with HLR corrections show a maximum deviation of less than 0.5 eV with respect to experimental values.
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Affiliation(s)
- Xuechen Zheng
- Department of Chemistry, The Johns Hopkins University, Baltimore, MD 21218, USA.
| | - Chaoqun Zhang
- Department of Chemistry, The Johns Hopkins University, Baltimore, MD 21218, USA.
| | - Zheqi Jin
- Department of Chemistry, University College London, London, WC1E 6BT, UK
| | - Stephen H Southworth
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Lan Cheng
- Department of Chemistry, The Johns Hopkins University, Baltimore, MD 21218, USA.
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4
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Vandaele E, Mališ M, Luber S. The ΔSCF method for non-adiabatic dynamics of systems in the liquid phase. J Chem Phys 2022; 156:130901. [PMID: 35395890 DOI: 10.1063/5.0083340] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Computational studies of ultrafast photoinduced processes give valuable insights into the photochemical mechanisms of a broad range of compounds. In order to accurately reproduce, interpret, and predict experimental results, which are typically obtained in a condensed phase, it is indispensable to include the condensed phase environment in the computational model. However, most studies are still performed in vacuum due to the high computational cost of state-of-the-art non-adiabatic molecular dynamics (NAMD) simulations. The quantum mechanical/molecular mechanical (QM/MM) solvation method has been a popular model to perform photodynamics in the liquid phase. Nevertheless, the currently used QM/MM embedding techniques cannot sufficiently capture all solute-solvent interactions. In this Perspective, we will discuss the efficient ΔSCF electronic structure method and its applications with respect to the NAMD of solvated compounds, with a particular focus on explicit quantum mechanical solvation. As more research is required for this method to reach its full potential, some challenges and possible directions for future research are presented as well.
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Affiliation(s)
- Eva Vandaele
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Momir Mališ
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Sandra Luber
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
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5
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Totani R, Ljubić I, Ciavardini A, Grazioli C, Galdenzi F, de Simone M, Coreno M. Frontier orbital stability of nitroxyl organic radicals probed by means of inner shell resonantly enhanced valence band photoelectron spectroscopy. Phys Chem Chem Phys 2022; 24:1993-2003. [PMID: 35018901 DOI: 10.1039/d1cp05264k] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have investigated the frontier orbitals of persistent organic radicals known as nitroxyls by resonant photoelectron spectroscopy (ResPES) under inner shell excitation. By means of this site-specific technique, we were able to disentangle the different atomic contributions to the outer valence molecular orbitals and examine several core-hole relaxation pathways involving the singly occupied molecular orbital (SOMO) localized on the nitroxyl group. To interpret the ResPES intensity trends, especially the strong enhancement of the SOMO ionized state at the N K-edge, we computed the Dyson spin orbitals (DSOs) pertaining to the transitions between the core-excited initial states and several of the singly ionized valence final states. We found that the computed vertical valence ionization potentials and norms of the DSOs are reasonably reliable when based on the long-range corrected CAM-B3LYP density functional. Thanks to their unpaired electrons, nitroxyls have recently found application in technological fields implying a spin control, such as spintronics and quantum computing. The present findings on the electronic structure of nitroxyl persistent radicals furnish important hints for their implementation in technological devices and, more in general, for the synthesis of new and stable organic radicals with tailored properties.
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Affiliation(s)
- R Totani
- ISM-CNR, LD2 Unit, Basovizza Area Science Park, 34149 Trieste, Italy.
| | - I Ljubić
- Division of Physical Chemistry, Ruđer Bošković Institute, Bijenička cesta 54, HR-10000 Zagreb, Croatia.
| | - A Ciavardini
- University of Nova Gorica, Vipavska 13, SI-5000 Nova Gorica, Slovenia
| | - C Grazioli
- IOM-CNR, Laboratorio TASC, Basovizza SS-14, km 163.5, 34149 Trieste, Italy
| | - F Galdenzi
- University of Nova Gorica, Vipavska 13, SI-5000 Nova Gorica, Slovenia
| | - M de Simone
- IOM-CNR, Laboratorio TASC, Basovizza SS-14, km 163.5, 34149 Trieste, Italy
| | - M Coreno
- ISM-CNR, LD2 Unit, Basovizza Area Science Park, 34149 Trieste, Italy.
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6
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Wasowicz TJ, Ljubic I, Kivimäki A, RICHTER R. Core-shell excitation of isoxazole at the C, N, and O K-edges – an experimental NEXAFS and theoretical TD-DFT study. Phys Chem Chem Phys 2022; 24:19302-19313. [DOI: 10.1039/d2cp02366k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The near-edge X-ray absorption fine structure (NEXAFS) spectra of the gas-phase isoxazole molecule have been measured by collecting total ion yields at the C, N, and O K-edges. The spectral...
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7
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Besley NA. Modeling of the spectroscopy of core electrons with density functional theory. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2021. [DOI: 10.1002/wcms.1527] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Nicholas A. Besley
- School of Chemistry, University of Nottingham University Park Nottingham UK
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8
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Banerjee S, Sokolov AY. Efficient implementation of the single-reference algebraic diagrammatic construction theory for charged excitations: Applications to the TEMPO radical and DNA base pairs. J Chem Phys 2021; 154:074105. [PMID: 33607870 DOI: 10.1063/5.0040317] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
We present an efficient implementation of the second- and third-order single-reference algebraic diagrammatic construction (ADC) theory for electron attachment and ionization energies and spectra [EA/IP-ADC(n), n = 2, 3]. Our new EA/IP-ADC program features spin adaptation for closed-shell systems, density fitting for efficient handling of the two-electron integral tensors, and vectorized and parallel implementation of tensor contractions. We demonstrate capabilities of our efficient implementation by applying the EA/IP-ADC(n) (n = 2, 3) methods to compute the photoelectron spectrum of the (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) radical, as well as the vertical and adiabatic electron affinities of TEMPO and two DNA base pairs (guanine-cytosine and adenine-thymine). The spectra and electron affinities computed using large diffuse basis sets with up to 1028 molecular orbitals are found to be in good agreement with the best available results from the experiment and theoretical simulations.
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Affiliation(s)
- Samragni Banerjee
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - Alexander Yu Sokolov
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
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9
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Ljubić I, Cvitaš MT, Grazioli C, Coreno M, Kazazić S, Novak I. Vibrationally resolved valence and core photoionization and photoexcitation spectra of an electron-deficient trivalent boron compound: the case of catecholborane. Phys Chem Chem Phys 2020; 22:25396-25407. [PMID: 33141120 DOI: 10.1039/d0cp04822d] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Compounds containing trivalent boron (TB) as the electron-deficient site(s) find numerous practical uses ranging from Lewis bases in organic synthesis to high-tech industry, with a number of novel applications anticipated. We present an experimental and theoretical study of the gas-phase valence photoionization (VUV-PES), core photoionization (XPS) and photoexcitation (NEXAFS) spectra of a representative TB compound catecholborane (CB). For modelling and assigning the spectra we used the ΔDFT and restricted single excitation space TD-DFT methods for the XPS and NEXAFS, and OVGF and EOM-CCSD for the VUV-PES. The vibrationally resolved structure was computed in the Franck-Condon (FC) and Herzberg-Teller (FCHT) approximations generally resulting in a good agreement with the observed spectral features. For the prediction of core-electron binding energies (CEBEs) several density functionals were tested. The best performance overall was furnished by ωB97X-D suggesting that including the dispersion correction is beneficial. The FCHT vibronic intensities are in clear discrepancy with the B 1s NEXAFS spectrum if the harmonic approximation is used for the B-H wagging mode both in the ground and in the first core-excited state. Instead, a much better agreement is obtained if the excited state potential is approximated to a symmetric double-well. The observed vibronic pattern could be a general fingerprint of the presence of TB centre(s), specifically, the transfer of the (core) density to the vacant boron p-orbital in the excited state.
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Affiliation(s)
- Ivan Ljubić
- Department of Physical Chemistry, Ruđer Bošković Institute, Bijenička cesta 54, HR-10000, Zagreb, Croatia.
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10
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Hait D, Haugen EA, Yang Z, Oosterbaan KJ, Leone SR, Head-Gordon M. Accurate prediction of core-level spectra of radicals at density functional theory cost via square gradient minimization and recoupling of mixed configurations. J Chem Phys 2020; 153:134108. [DOI: 10.1063/5.0018833] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Diptarka Hait
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Eric A. Haugen
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Zheyue Yang
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Katherine J. Oosterbaan
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Stephen R. Leone
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - Martin Head-Gordon
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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11
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Besley NA. Density Functional Theory Based Methods for the Calculation of X-ray Spectroscopy. Acc Chem Res 2020; 53:1306-1315. [PMID: 32613827 DOI: 10.1021/acs.accounts.0c00171] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The availability of new light sources combined with the realization of the unique capabilities of spectroscopy in the X-ray region has driven tremendous advances in the field of X-ray spectroscopy. Currently, these techniques are emerging as powerful analytical tools for the study of a wide range of problems encompassing liquids, materials, and biological systems. Time-resolved measurements add a further dimension to X-ray spectroscopy, opening up the potential to resolve ultrafast chemical processes at an atomic level. X-ray spectroscopy encompasses a range of techniques which provide complementary information, and these include X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), X-ray emission spectroscopy (XES), and resonant inelastic X-ray scattering (RIXS). In many studies, the interpretation of the experimental data relies upon calculations to enable the nature of the underlying molecular structure, electronic structure, and bonding to be revealed. Density functional theory (DFT) based methods are some of the most widely used methods for the simulation of X-ray spectra. In this Account, we focus on our recent contributions to the simulation of a range of X-ray spectroscopic techniques using DFT and linear-response time-dependent density functional theory (TDDFT) and show how these methods can provide a computational toolkit for the simulation of X-ray spectroscopy. The importance of the exchange-correlation functional for the calculation of XAS is discussed, and the introduction of short-range corrected functionals is described. The application of these calculations to study large systems through the use of efficient implementations of TDDFT will be highlighted, with the use of these methods illustrated through studies of ionic liquids and transition metal complexes. The extension of TDDFT to calculate XES through the use of a reference determinant for the core-ionized state will be described, and the factors that affect the accuracy of the computed spectra discussed. The application of these approaches will be illustrated through the study of a range of organic molecules and transition metal complexes, which also show how going beyond the dipole approximation in determining the transition intensities can be critical. The application of these approaches to the simulation of the RIXS spectrum of water will also be described, highlighting how ultrafast dynamics on the femtoscale time scale are evident in the measured spectra. In these calculations, the description of the core-ionized and core-excited states becomes increasingly important, and the role of the basis set in accurately describing these states will be explored.
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Affiliation(s)
- Nicholas A. Besley
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
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12
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Zheng X, Liu J, Doumy G, Young L, Cheng L. Hetero-site Double Core Ionization Energies with Sub-electronvolt Accuracy from Delta-Coupled-Cluster Calculations. J Phys Chem A 2020; 124:4413-4426. [DOI: 10.1021/acs.jpca.0c00901] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xuechen Zheng
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Junzi Liu
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Gilles Doumy
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Linda Young
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Lan Cheng
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
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13
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Oosterbaan KJ, White AF, Hait D, Head-Gordon M. Generalized single excitation configuration interaction: an investigation into the impact of the inclusion of non-orthogonality on the calculation of core-excited states. Phys Chem Chem Phys 2020; 22:8182-8192. [DOI: 10.1039/c9cp06592j] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
In this paper, we investigate different non-orthogonal generalizations of the configuration interaction with single substitutions (CIS) method and their impact on the calculation of core-excited states.
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Affiliation(s)
| | - Alec F. White
- Division of Chemistry and Chemical Engineering
- California Institute of Technology
- Pasadena
- USA
| | - Diptarka Hait
- Department of Chemistry
- University of California
- Berkeley
- USA
- Chemical Sciences Division
| | - Martin Head-Gordon
- Department of Chemistry
- University of California
- Berkeley
- USA
- Chemical Sciences Division
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14
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Zheng X, Cheng L. Performance of Delta-Coupled-Cluster Methods for Calculations of Core-Ionization Energies of First-Row Elements. J Chem Theory Comput 2019; 15:4945-4955. [DOI: 10.1021/acs.jctc.9b00568] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xuechen Zheng
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Lan Cheng
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
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15
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Tenorio BNC, Moitra T, Nascimento MAC, Rocha AB, Coriani S. Molecular inner-shell photoabsorption/photoionization cross sections at core-valence-separated coupled cluster level: Theory and examples. J Chem Phys 2019; 150:224104. [PMID: 31202254 DOI: 10.1063/1.5096777] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Oxygen, nitrogen, and carbon K-shell photoabsorption and photoionization cross sections have been calculated within core-valence-separated coupled cluster (CC) linear response theory for a number of molecular systems, namely, water, ammonia, ethylene, carbon dioxide, acetaldehyde, furan, and pyrrole. The cross sections below and above the K-edge core ionization thresholds were obtained, on the same footing, from L2 basis set calculations of the discrete electronic pseudospectrum yielded by an asymmetric-Lanczos-based formulation of CC linear response theory at the CC singles and doubles (CCSD) and CC singles and approximate doubles (CC2) levels. An analytic continuation procedure for both discrete and continuum cross sections as well as a Stieltjes imaging procedure for the photoionization cross section were applied and the results critically compared.
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Affiliation(s)
- Bruno Nunes Cabral Tenorio
- Instituto de Química, Universidade Federal do Rio de Janeiro, UFRJ, Av. Athos da Silveira Ramos, 149, Rio de Janeiro, RJ 21941-909, Brazil
| | - Torsha Moitra
- DTU Chemistry, Technical University of Denmark, Kemitorvet, Building 207, DK-2800 Kongens Lyngby, Denmark
| | - Marco Antonio Chaer Nascimento
- Instituto de Química, Universidade Federal do Rio de Janeiro, UFRJ, Av. Athos da Silveira Ramos, 149, Rio de Janeiro, RJ 21941-909, Brazil
| | - Alexandre Braga Rocha
- Instituto de Química, Universidade Federal do Rio de Janeiro, UFRJ, Av. Athos da Silveira Ramos, 149, Rio de Janeiro, RJ 21941-909, Brazil
| | - Sonia Coriani
- DTU Chemistry, Technical University of Denmark, Kemitorvet, Building 207, DK-2800 Kongens Lyngby, Denmark
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16
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Wang Z, Paquette JA, Staroverov VN, Gilroy JB, Sham TK. X-ray Absorption Near-Edge Structure Spectroscopy of a Stable 6-Oxoverdazyl Radical and Its Diamagnetic Precursor. J Phys Chem A 2019; 123:323-328. [PMID: 30582809 DOI: 10.1021/acs.jpca.8b11639] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The electronic structure of 1,3,5-triphenyl-6-oxoverdazyl, a heteroatom-rich stable organic radical, and its diamagnetic 1,3,5-triphenyl-6-oxotetrazane precursor are probed using X-ray absorption near-edge structure (XANES) spectroscopy. The N K-edge XANES spectra of the 6-oxoverdazyl radical contain strong N 1s → π* resonances for each set of equivalent nitrogen atoms. The fact that these resonances are absent from the analogous spectra of the 6-oxotetrazane, whereas the O K-edge and C K-edge XANES spectra of both species are very similar, demonstrates that the unpaired electron of the radical is localized primarily on the N atoms of the 6-oxoverdazyl heterocycle. The O K-edge XANES spectra of both species contain strong O 1s → π* (C═O) peaks, but the peak of the radical is red-shifted by 0.5 eV relative to that of the 6-oxotetrazane, which indicates that the C═O bond in the radical is part of a larger π-conjugated system. The proposed interpretations of the XANES spectra are aided by density-functional calculations.
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17
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Tenorio BNC, Oliveira RR, Nascimento MAC, Rocha AB. Coupled Cluster and Time-Dependent Density Functional Theory Description of Inner Shell Photoabsorption Cross Sections of Molecules. J Chem Theory Comput 2018; 14:5324-5338. [DOI: 10.1021/acs.jctc.8b00375] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Bruno Nunes Cabral Tenorio
- UFRJ - Universidade Federal do Rio de Janeiro, Instituto
de Química, Av. Athos da Silveira Ramos, 149, Rio de Janeiro 21941-909, Brasil
| | - Ricardo Rodrigues Oliveira
- UFRJ - Universidade Federal do Rio de Janeiro, Instituto
de Química, Av. Athos da Silveira Ramos, 149, Rio de Janeiro 21941-909, Brasil
| | - Marco Antonio Chaer Nascimento
- UFRJ - Universidade Federal do Rio de Janeiro, Instituto
de Química, Av. Athos da Silveira Ramos, 149, Rio de Janeiro 21941-909, Brasil
| | - Alexandre Braga Rocha
- UFRJ - Universidade Federal do Rio de Janeiro, Instituto
de Química, Av. Athos da Silveira Ramos, 149, Rio de Janeiro 21941-909, Brasil
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18
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Ljubić I, Kivimäki A, Coreno M, Kazazić S, Novak I. Characterisation of the electronic structure of galvinoxyl free radical by variable energy UPS, XPS and NEXAFS spectroscopy. Phys Chem Chem Phys 2018; 20:2480-2491. [DOI: 10.1039/c7cp07266j] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
UPS, XPS and NEXAFS spectra of persistent free radical galvinoxyl are assigned using theoretical ΔDFT and TDDFT methods.
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Affiliation(s)
- Ivan Ljubić
- Department of Physical Chemistry
- Ruđer Bošković Institute
- HR-10000 Zagreb
- Croatia
| | | | | | - Saša Kazazić
- Department of Physical Chemistry
- Ruđer Bošković Institute
- HR-10000 Zagreb
- Croatia
| | - Igor Novak
- Charles Sturt University
- Orange NSW 2800
- Australia
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19
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Besley NA. Fast Time-Dependent Density Functional Theory Calculations of the X-ray Absorption Spectroscopy of Large Systems. J Chem Theory Comput 2016; 12:5018-5025. [DOI: 10.1021/acs.jctc.6b00656] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Nicholas A. Besley
- School of Chemistry, University of Nottingham, University
Park, Nottingham, NG7 2RD, U.K
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