36 results on '"vibronic couplings"'
Search Results
2. Dynamics on accurate coupled artificial neural network based potential surfaces : NO_3^- photodetachment spectra
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Viel, Alexandra, Williams, David M. G., Eisfeld, Wolfgang, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), and Universität Bielefeld = Bielefeld University
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[PHYS]Physics [physics] ,MCTDH ,Vibronic couplings ,Quantum dynamics ,Molecular physics ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 2022
3. Photodetachment spectrum of NO3-: Jahn-Teller effect and artificial neuron network
- Author
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Viel, Alexandra, Williams, David M. G., Eisfeld, Wolfgang, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Fakultät für Chemie [Universität Bielefeld], Universität Bielefeld, Viel, Alexandra, Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
[PHYS]Physics [physics] ,MCTDH ,Vibronic couplings ,Artificial Neuron Networks ANN ,Quantum dynamics ,Molecular physics ,ComputingMilieux_MISCELLANEOUS ,[PHYS] Physics [physics] - Abstract
International audience
- Published
- 2021
4. Accurate quantum dynamics simulation of the photodetachment spectrum of the nitrate anion (NO3−) based on an artificial neural network diabatic potential model
- Author
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Alexandra Viel, David M. G. Williams, Wolfgang Eisfeld, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Theoretische Chemie, Universität Bielefeld, Germany, Universität Bielefeld = Bielefeld University, Ei375/6-2, Deutsche Forschungsgemeinschaft, 40442PD, PHC/DAAD Procope, and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)
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Physics ,[PHYS]Physics [physics] ,010304 chemical physics ,Wave packet ,Quantum dynamics ,Diabatic ,Vibronic couplings ,General Physics and Astronomy ,Electron ,010402 general chemistry ,01 natural sciences ,Molecular physics ,Hot band ,0104 chemical sciences ,Vibronic coupling ,MCTDH ,Excited state ,0103 physical sciences ,Artificial Neuron Networks ANN ,Physical and Theoretical Chemistry ,Physics::Chemical Physics ,Ground state ,Spectroscopy - Abstract
International audience; The photodetachment spectrum of the nitrate anion (NO − 3) is simulated from first principles using wavepacket quantum dynamics propagation and a newly developed accurate full-dimensional fully coupled five state diabatic potential model. This model utilizes the recently proposed complete nuclear permutation inversion invariant artificial neural network diabatization technique [D. M. G. Williams and W. Eisfeld, J. Phys. Chem. A 124, 7608 (2020)]. The quantum dynamics simulations are designed such that temperature effects and the impact of near threshold detachment are taken into account. Thus, the two available experiments at high temperature and at cryogenic temperature using the slow electron velocity-map imaging technique can be reproduced in very good agreement. These results clearly show the relevance of hot bands and vibronic coupling between theX 2 A ′ 2 ground state and theB 2 E ′ excited state of the neutral radical. This together with the recent experiment at low temperature gives further support for the proper assignment of the ν 3 fundamental, which has been debated for many years. An assignment of a not yet discussed hot band line is also proposed.
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- 2021
5. Core-hole localization and ultra-fast dissociation in SF6
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Ekholm, V, Chiuzbaian, G. S., Sathe, C., Nicolaou, A., Guarise, M., Simon, M., Jaouen, N., Luning, J., Hague, C. F., Gel'mukhanov, F., Odelius, M., Björneholm, Olle, Rubensson, Jan-Erik, Ekholm, V, Chiuzbaian, G. S., Sathe, C., Nicolaou, A., Guarise, M., Simon, M., Jaouen, N., Luning, J., Hague, C. F., Gel'mukhanov, F., Odelius, M., Björneholm, Olle, and Rubensson, Jan-Erik
- Abstract
Resonant inelastic x-ray scattering spectra excited at the fluorine K resonances of SF(6)have been recorded. While a small but significant propensity for electronically parity-allowed transitions is found, the observation of parity-forbidden electronic transitions is attributed to vibronic coupling that breaks the global inversion symmetry of the electronic wavefunction and localizes the core hole. The dependence of the scattering cross section on the polarization of the incident radiation and the scattering angle is interpreted in terms of local pi/sigma symmetry around the S-F bond. This symmetry selectivity prevails during the dissociation that occurs during the scattering process.
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- 2020
- Full Text
- View/download PDF
6. Non adiabatic effects in the photodetachment spectra of NO3–: Jahn-Teller effect and artificial neural network
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Viel, Alexandra, Viel, Alexandra, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)
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[PHYS]Physics [physics] ,MCTDH ,Artificial Neuron Networks ANN ,Vibronic couplings ,Quantum dynamics ,Molecular physics ,ComputingMilieux_MISCELLANEOUS ,Spectroscopy ,[PHYS] Physics [physics] - Abstract
International audience
- Published
- 2021
7. Couplages non-adiabatiques et spectroscopie : cas du radical NO3 [Conférence plénière]
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Viel, Alexandra, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)
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[PHYS]Physics [physics] ,MCTDH ,Vibronic couplings ,Quantum dynamics ,Molecular physics ,ComputingMilieux_MISCELLANEOUS - Abstract
National audience
- Published
- 2020
8. A few more neurons to tackle the NO3 non-adiabatic effects
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Viel, Alexandra, Viel, Alexandra, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)
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[PHYS]Physics [physics] ,MCTDH ,Vibronic couplings ,Quantum dynamics ,Molecular physics ,ComputingMilieux_MISCELLANEOUS ,[PHYS] Physics [physics] - Abstract
International audience
- Published
- 2020
9. Valence one-electron and shake-up ionisation bands of polycyclic aromatic hydrocarbons. IV. The dibenzanthracene species
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Deleuze, Michael S.
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SCISSION (Chemistry) , *HYDROCARBONS , *SPECTRUM analysis , *DENSITY functionals - Abstract
Abstract: A comprehensive study of the He (I) ultra-violet photoelectron spectra of the 1.2,3.4; 1.2,5.6 and 1.2,7.8 isomers of dibenzanthracene up to the double ionisation threshold at ∼18eV is presented with the aid of one-particle Green’s Function calculations performed using the outer-valence Green’s Function (OVGF) approach and the third-order algebraic diagrammatic construction [ADC(3)] scheme, along with basis sets of improving quality. Suited extrapolations of the ADC(3) results for the one-electron energies characterising the π-band system (ε b <10eV) to Dunning’s correlation consistent basis set of triple zeta quality (cc-pVTZ) enable theoretical insights into HeI measurements which approach chemical accuracy (1kcal/mol or 43.4meV). In contrast, a confrontation of simulated spectral envelopes with high-resolution He I photoelectron spectra indicates that polycyclic aromatic molecules with sterically overcrowded bay regions are more susceptible to undergo vibronic coupling complications at the σ-ionisation onset. OVGF/cc-pVDZ or OVGF/cc-pVTZ pole strengths smaller than 0.85 systematically corroborate a breakdown of the orbital (or one-electron) picture of ionisation at the ADC(3)/6-31G levels. The extent of shake-up bands is correspondingly related to topological, structural and magnetic criteria of aromaticity. Comparison is made with calculations of the lowest doublet–doublet excitation energies of the related radical cations, by means of time-dependent density functional theory (TDDFT). [Copyright &y& Elsevier]
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- 2006
- Full Text
- View/download PDF
10. Diabatic neural network potentials for accurate vibronic quantum dynamics -The test case of planar NO3
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David M. G. Williams, Alexandra Viel, Wolfgang Eisfeld, Theoretische Chemie, Universität Bielefeld, Germany, Universität Bielefeld = Bielefeld University, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Deutsche Forschungsgemeinschaft, 40442PD, Deutscher Akademischer Austauschdienst, PROCOPE project number 40442PD, and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)
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Physics ,[PHYS]Physics [physics] ,010304 chemical physics ,Quantum dynamics ,Diabatic ,Ab initio ,Vibronic couplings ,General Physics and Astronomy ,010402 general chemistry ,01 natural sciences ,Potential energy ,0104 chemical sciences ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,Vibronic coupling ,Matrix (mathematics) ,MCTDH ,0103 physical sciences ,Artificial Neuron Networks ANN ,Statistical physics ,[PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph] ,Physical and Theoretical Chemistry ,Molecular physics ,Eigenvalues and eigenvectors ,Ansatz - Abstract
International audience; A recently developed scheme to produce high-dimensional coupled diabatic potential energy surfaces (PESs) based on artificial neural networks (ANNs) [D. M. G. Williams and W. Eisfeld, J. Chem. Phys. 149, 204106 (2019)] is tested for its viability for quantum dynamics applications. The method, capable of reproducing high-quality ab initio data with excellent accuracy, utilizes simple coupling matrices to produce a basic low-order diabatic potential matrix as an underlying backbone for the model. This crude model is then refined by making its expansion coefficients geometry-dependent by the output neurons of the ANN. This structure, strongly guided by a straightforward physical picture behind nonadiabatic coupling, combines structural simplicity with high accuracy, reproducing ab initio data without introducing unphysical artifacts to the surface, even for systems with complicated electronic structure. The properties of diabatic potentials obtained by this method are tested thoroughly in the present study. Vibrational/vibronic eigenstates are computed on theX andà states of NO 3 , a notoriously difficult Jahn-Teller system featuring strong nonadiabatic couplings and complex spectra. The method is investigated in terms of how consistently it produces dynamics results for PESs of similar (fitting) quality and how the results depend on the ANN size and ANN topography. A central aspect of this work is to understand the convergence properties of the new method in order to evaluate its predictive power. A previously developed, high-quality model utilizing a purely (high-order) polynomial ansatz is used as a reference to showcase improvements of the overall quality which can be obtained by the new method.
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- 2019
11. Quantum dynamics and geometric phase in E ⊗ e Jahn-Teller systems with general Cnv symmetry
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David M. G. Williams, Alexandra Viel, Wolfgang Eisfeld, Thomas Weike, Theoretische Chemie, Universität Bielefeld, Germany, Universität Bielefeld = Bielefeld University, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), PHC PROCOPE 40442PD, and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)
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Physics ,[PHYS]Physics [physics] ,010304 chemical physics ,Jahn–Teller effect ,Quantum dynamics ,Diabatic ,Vibronic couplings ,General Physics and Astronomy ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,Vibronic coupling ,symbols.namesake ,Geometric phase ,Quantum mechanics ,0103 physical sciences ,Potential energy surface ,symbols ,[PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph] ,Physical and Theoretical Chemistry ,Adiabatic process ,Hamiltonian (quantum mechanics) ,Molecular physics - Abstract
International audience; E ⊗ e Jahn-Teller (JT) systems are considered the prototype of symmetry-induced conical intersections and of the corresponding geometric phase effect (GPE). For decades, this has been analyzed for the most common case originating from C 3v symmetry and these results usually were generalized. In the present work, a thorough analysis of the JT effect, vibronic coupling Hamiltonians, GPE, and the effect on spectro-scopic properties is carried out for general Cnv symmetric systems (and explicitly for n = 3-8). It turns out that the C 3v case is much less general than often assumed. The GPE due to the vibronic Hamiltonian depends on the leading coupling term of a diabatic representation of the problem, which is a result of the explicit n, α, and β values of a Cnv Eα ⊗ e β system. Furthermore, the general existence of n/m (m ∈ N depending on n, α, and β) equivalent minima on the lower adiabatic sheet of the potential energy surface (PES) leads to tunneling multiplets of n/m states (state components). These sets can be understood as local vibrations of the atoms around their equilibrium positions within each of the local PES wells symmetrized over all equivalent wells. The local vibrations can be classified as tangential or radial vibrations, and the quanta in the tangential mode together with the GPE determine the level ordering within each of the vibronic multiplets. Our theoretical predictions derived analytically are tested and supported by numerical model simulations for all possible Eα ⊗ e β cases for Cnv symmetric systems with n = 3-8. The present interpretation allows for a full understanding of the complex JT spectra of real systems, at least for low excitation energies. This also opens a spectroscopic way to show the existence or absence of GPEs. Published under license by AIP Publishing. https://doi.
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- 2019
12. NO3 radical in full dimension including non-adiabatic couplings
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Viel, Alexandra, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), and Viel, Alexandra
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[PHYS]Physics [physics] ,MCTDH ,Vibronic couplings ,Quantum dynamics ,Molecular physics ,ComputingMilieux_MISCELLANEOUS ,[PHYS] Physics [physics] - Abstract
National audience
- Published
- 2018
13. A Joint Theoretical and Experimental Study of the Behavior of the DIDS Inhibitor and its Derivatives
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Anaïs Goupille, Fabrice Fleury, Titouan Jaunet-Lahary, Jérôme Graton, Denis Jacquemin, Adèle D. Laurent, Chimie Et Interdisciplinarité : Synthèse, Analyse, Modélisation (CEISAM), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Mécanisme et régulation de la réparation de l’ADN [Nantes], Unité de fonctionnalité et ingénierie de protéines (UFIP), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), and Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)
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Models, Molecular ,vibronic couplings ,Protonation ,4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid ,010402 general chemistry ,Photochemistry ,01 natural sciences ,chemistry.chemical_compound ,Isomerism ,Computational chemistry ,0103 physical sciences ,stilbene sulfonic acid ,Physical and Theoretical Chemistry ,010304 chemical physics ,Vis spectroscopy ,Atomic and Molecular Physics, and Optics ,Redshift ,UV ,0104 chemical sciences ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,Solvent ,Wavelength ,Vibronic coupling ,chemistry ,Spectrophotometry ,DIDS ,density functional calculations ,Quantum Theory ,Thermodynamics ,Density functional theory ,Protons ,solvent reorganization ,Cis–trans isomerism - Abstract
International audience; 4,4-Diisothiocyanostilbene-2,2-disulfonic acid (DIDS) is a well-known ion-exchange inhibitor targeting cardiac functions and indirectly impeding both radio- and chemo-resistance. A joint computational and experimental study is presented to provide deeper insights into DIDS and other members of this family of compounds. To this end, we applied state-of-the-art density functional theory (DFT) and time-dependent DFT methods, in addition to measuring the optical properties. The experimental data show that such compounds are highly sensitive to their environment and that the optical properties change within as little time as 7h. However, the optical properties of DIDS are similar in various acidic/basic environments, which were confirmed by pK(a) computations on both cis and trans isomers. The protonation analysis also highlights that the singly protonated form of DIDS behaves like a proton sponge compound. The experimentally observed redshift that can be seen when going from water to DMSO was reproduced solely by using the solvation model based on density, although the polarization continuum model and implicit/explicit hybrid schemes were also tested. The characteristic broadening of the absorption peak in water and the vibronic fine structure in DMSO were also reproduced thanks to vibronic coupling simulations associated with the solvent reorganization energy. For other stilbene derivatives, a correlation is found between the maximum absorption wavelength and the Hammett parameters.
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- 2016
14. Vibronisches Spektralverhalten von Molekülen: XIV. Zum Einfluß der vibronischen Kopplung auf die S-S-Absorption und Fluoreszenz von ausgewählten 1,3-Diketonato-bor-komplexen im Rahmen der Herzberg-Teller-Näherung.
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Gustav, Klaus and Storch, Michael
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Based upon completely-optimized S and S molecular geometries the vibrational structures of S-S absorption and fluorescence transitions of selected 1,3-diketonato boron complexes being differently substituted, are calculated within the Herzberg-Teller approach taking into account vibronic coupling contributions. In dependence on substituted diketone as well as on the co-ligand, the influence of vibronic coupling and the consequences of intensity borrowing on the spectral behaviour in absorption and fluorescence are found to be quite different for the studied boron complexes. Consequently, for some complexes their spectroscopic properties may be interpreted exclusively by means of the Herzberg-Teller approach. An analysis of the relevant vibrational modes is given. [ABSTRACT FROM AUTHOR]
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- 1990
- Full Text
- View/download PDF
15. NO3 full-dimensional potential energy surfaces and ground state vibrational levels revisited
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Wolfgang Eisfeld, Alexandra Viel, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Theoretische Chemie, Universität Bielefeld, Germany, Universität Bielefeld = Bielefeld University, Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique de Rennes ( IPR ), Université de Rennes 1 ( UR1 ), Université de Rennes ( UNIV-RENNES ) -Université de Rennes ( UNIV-RENNES ) -Centre National de la Recherche Scientifique ( CNRS ), and Bielefeld University
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[PHYS]Physics [physics] ,Range (particle radiation) ,[ PHYS ] Physics [physics] ,010304 chemical physics ,Chemistry ,Quantum dynamics ,Diabatic ,Vibronic couplings ,General Physics and Astronomy ,010402 general chemistry ,01 natural sciences ,Potential energy ,0104 chemical sciences ,Dipole ,MCTDH ,Ab initio quantum chemistry methods ,0103 physical sciences ,Potential energy surface ,Physical and Theoretical Chemistry ,Atomic physics ,Ground state ,Molecular physics ,ComputingMilieux_MISCELLANEOUS - Abstract
A new full-dimensional (6D) diabatic potential energy surface (PES) model is presented representing the five lowest PESs corresponding to the X 2 A 2 ′ , A 2 E ″ , and B 2 E ′ electronic states of the nitrate radical (NO3). It is based on high-level ab initio calculations of roughly 90000 energy data over a wide range of nuclear configurations and represents the energies with a root mean-squares (rms) error of about 100 cm−1. An accurate dipole surface was developed for the X state as well. The new PES model is used to re-investigate the infra-red (IR) spectrum corresponding to the electronic ground state by full dimensional quantum dynamics simulations. Vibrational eigenstates, IR transition probabilities, and isotopic shifts are computed and analyzed. Levels up to 2000 cm−1 are obtained and show good to excellent agreement with known experimental values. Some larger deviations are observed and discussed as well. The new results are in agreement with previous theoretical studies that the disputed ν 3 fundamental corresponds to a frequency of roughly 1022 cm−1 and that the prominent experimental feature observed at 1492 cm−1 is due to the 3 1 4 1 ( e ′ ) combination mode. Observed discrepancies in the IR intensities may be explained by coupling to the B state which is also analysed by diabatic decomposition of the eigenstates.
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- 2018
16. Symmetry, geometric phase and spectroscopy
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Eisfeld, Wolfgang, Weike, Thomas, Williams, David M. G., Viel, Alexandra, Viel, Alexandra, Universität Bielefeld = Bielefeld University, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Theoretische Chemie, Universität Bielefeld, Germany, Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)
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[PHYS]Physics [physics] ,Quantum Dynamics ,Vibronic couplings ,Molecular physics ,ComputingMilieux_MISCELLANEOUS ,[PHYS] Physics [physics] - Abstract
International audience
- Published
- 2018
17. Vibronic eigenstates and the geometric phase effect in the 2 E″ state of NO 3
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Wolfgang Eisfeld, Alexandra Viel, Faculty of Chemistry, Universität Bielefeld = Bielefeld University, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), INTEGER project included in the No. EU 7ePC/2007-2013 program with the Convention No. 266638, European Project: 266638,EC:FP7:SiS,FP7-SCIENCE-IN-SOCIETY-2010-1,INTEGER(2011), and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)
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Quantum dynamics ,Jahn–Teller effect ,General Physics and Astronomy ,010402 general chemistry ,01 natural sciences ,MCTDH ,Quantum mechanics ,0103 physical sciences ,Physics::Atomic and Molecular Clusters ,Vibronic spectroscopy ,Physics::Chemical Physics ,Physical and Theoretical Chemistry ,Quantum tunnelling ,[PHYS]Physics [physics] ,010304 chemical physics ,Chemistry ,Vibronic couplings ,Hartree ,0104 chemical sciences ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,Vibronic coupling ,Geometric phase ,[PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph] ,Atomic physics ,Ground state ,Molecular physics - Abstract
The E-2 '' state of NO3, a prototype for the Jahn-Teller effect, has been an enigma and a challenge for a long time for both experiment and theory. We present a detailed theoretical study of the vibronic quantum dynamics in this electronic state, uncovering the effects of tunnelling, geometric phase, and symmetry. To this end, 45 vibronic levels of NO3 in the E-2 '' state are determined accurately and analyzed thoroughly. The computation is based on a high quality diabatic potential representation of the two-sheeted surface of the E-2 '' state developed by us [W. Eisfeld et al., J. Chem. Phys. 140, 224109 (2014)] and on the multi-configuration time dependent Hartree approach. The vibrational eigenstates of the NO3- anion are determined and analyzed as well to gain a deeper understanding of the symmetry properties of such D-3h symmetric systems. To this end, 61 eigenstates of the NO3- anion ground state are computed using the single sheeted potential surface of the (1)A(1) state published in the same reference quoted above. The assignments of both the vibrational and vibronic levels are discussed. A simple model is proposed to rationalize the computed NO3 spectrum strongly influenced by the Jahn-Teller couplings, the associated geometric phase effect, and the tunnelling. Comparison with the available spectroscopic data is also presented. Published by AIP Publishing.
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- 2017
18. NO3 in the ^2 E' state: vibronic eigenstates and geometric phase
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Viel, Alexandra, Eisfeld, Wolfgang, Viel, Alexandra, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Theoretische Chemie, Universität Bielefeld, Germany, Universität Bielefeld = Bielefeld University, and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)
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[PHYS]Physics [physics] ,MCTDH ,[CHIM] Chemical Sciences ,Vibronic couplings ,[CHIM]Chemical Sciences ,Quantum dynamics ,Molecular physics ,ComputingMilieux_MISCELLANEOUS ,[PHYS] Physics [physics] - Abstract
International audience
- Published
- 2017
19. Theoretical insights on non-adiabatic effects in the NO3 radical
- Author
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Viel, Alexandra, Eisfeld, Wolfgang, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Theoretische Chemie, Universität Bielefeld, Germany, Universität Bielefeld = Bielefeld University, Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), and Viel, Alexandra
- Subjects
[PHYS]Physics [physics] ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,[CHIM.THEO] Chemical Sciences/Theoretical and/or physical chemistry ,MCTDH ,Vibronic couplings ,Quantum dynamics ,Molecular physics ,ComputingMilieux_MISCELLANEOUS ,[PHYS] Physics [physics] - Abstract
International audience
- Published
- 2015
20. Vibronic levels of NO3: the 2E' dark electronic state
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Viel, Alexandra, Viel, Alexandra, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)
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[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,[CHIM.THEO] Chemical Sciences/Theoretical and/or physical chemistry ,[PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph] ,MCTDH ,Vibronic couplings ,Quantum dynamics ,Molecular physics ,ComputingMilieux_MISCELLANEOUS ,[PHYS.QPHY] Physics [physics]/Quantum Physics [quant-ph] - Abstract
International audience
- Published
- 2015
21. Effects of higher order Jahn-Teller coupling on the nuclear dynamics
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Alexandra Viel, Wolfgang Eisfeld, Theoretische Chemie, TU Munchen, Germany, Department of Chemistry, and Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM)-Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM)
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Jahn–Teller effect ,Diabatic ,General Physics and Astronomy ,010402 general chemistry ,01 natural sciences ,symbols.namesake ,MCTDH ,[PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph] ,Quantum mechanics ,0103 physical sciences ,Quantum dynamics ,Physical and Theoretical Chemistry ,010304 chemical physics ,Chemistry ,Autocorrelation ,Degenerate energy levels ,Anharmonicity ,Vibronic couplings ,Potential energy ,0104 chemical sciences ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,Vibration ,symbols ,Condensed Matter::Strongly Correlated Electrons ,Atomic physics ,Molecular physics ,Hamiltonian (quantum mechanics) - Abstract
In this paper effects of higher order Jahn-Teller coupling terms on the nonadiabatic dynamics are studied. Of particular interest is the case when the potential energy surfaces of the degenerate state show pronounced anharmonicity. In order to demonstrate the effects a two-dimensional E multiply sign in circle e Jahn-Teller model system is treated which is based on the e(') stretching vibration of the photoactive (2)E(') state of NO(3) as a realistic example. The sixth order E multiply sign in circle e Jahn-Teller Hamiltonian is derived in the diabatic representation which is valid for any system with a C(3) rotation axis. This diabatization scheme is compared to lower-order Jahn-Teller Hamiltonians and to symmetry adapted as well as ad hoc approximations. Lower-order potentials result in pronounced quantitative and qualitative differences in the dynamics, including differences in the evolution of mean values, the autocorrelation functions (and thus the corresponding spectra), and the electronic population evolution. In the particular example treated, the results of fourth and fifth order potentials are very similar to the sixth order reference system. In contrast, the approximate sixth order Hamiltonians, though the corresponding adiabatic surfaces seem to be nearly identical, results in pronounced differences. The possible consequences for the dynamics of realistic systems with higher dimensionality are briefly discussed.
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- 2004
22. Non-Adiabatic Couplings and Dissociation: NO3 Radical
- Author
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Viel, Alexandra, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Launay, Jean-Michel, and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
[PHYS]Physics [physics] ,polyatomic molecules ,Vibronic couplings ,dissociation ,[PHYS] Physics [physics] ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,[CHIM.THEO] Chemical Sciences/Theoretical and/or physical chemistry ,MCTDH ,[PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph] ,non adiabatic couplings ,Quantum dynamics ,Molecular physics ,[PHYS.QPHY] Physics [physics]/Quantum Physics [quant-ph] ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 2014
23. Full-dimensional diabatic potential energy surfaces including dissociation: The E-2 ' state of NO3
- Author
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Alexandra Viel, Olivier Vieuxmaire, Wolfgang Eisfeld, Universität Bielefeld = Bielefeld University, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Theoretische Chemie, Universität Bielefeld, Germany, Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
[PHYS]Physics [physics] ,Stochastic process ,Chemistry ,Quantum dynamics ,Diabatic ,Vibronic couplings ,General Physics and Astronomy ,Hartree ,Potential energy ,Computational physics ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,MCTDH ,[PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph] ,Ab initio quantum chemistry methods ,Potential energy surface ,Physical and Theoretical Chemistry ,Atomic physics ,Ground state ,Molecular physics - Abstract
International audience; A scheme to produce accurate full-dimensional coupled diabatic potential energy surfaces including dissociative regions and suitable for dynamical calculations is proposed. The scheme is successfully applied to model the two-sheeted surface of the 2E″ state of the NO3 radical. An accurate potential energy surface for the NO−3NO3− anion ground state is developed as well. Both surfaces are based on high-level ab initio calculations. The model consists of a diabatic potential matrix, which is expanded to higher order in terms of symmetry polynomials of symmetry coordinates. The choice of coordinates is key for the accuracy of the obtained potential energy surfaces and is discussed in detail. A second central aspect is the generation of reference data to fit the expansion coefficients of the model for which a stochastic approach is proposed. A third ingredient is a new and simple scheme to handle problematic regions of the potential energy surfaces, resulting from the massive undersampling by the reference data unavoidable for high-dimensional problems. The final analytical diabatic surfaces are used to compute the lowest vibrational levels of NO−3NO3− and the photo-electron detachment spectrum of NO−3NO3− leading to the neutral radical in the 2E″ state by full dimensional multi-surface wave-packet propagation for NO3 performed using the Multi-Configuration Time Dependent Hartree method. The achieved agreement of the simulations with available experimental data demonstrates the power of the proposed scheme and the high quality of the obtained potential energy surfaces.
- Published
- 2014
24. A new approach to anharmonicity and dissociation in vibronically coupled systems
- Author
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Eisfeld, Wolfgang, Viel, Alexandra, Universität Bielefeld = Bielefeld University, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Theoretische Chemie, Universität Bielefeld, Germany, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), and Viel, Alexandra
- Subjects
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,[PHYS]Physics [physics] ,[CHIM.THEO] Chemical Sciences/Theoretical and/or physical chemistry ,MCTDH ,Vibronic couplings ,Quantum dynamics ,ComputingMilieux_MISCELLANEOUS ,[PHYS] Physics [physics] - Abstract
International audience
- Published
- 2010
25. The NO3 dissociative system: coupled potential energy surfaces and multi-surface dynamics
- Author
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Vieuxmaire, Olivier, Viel, Alexandra, Eisfeld, Wolfgang, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Theoretische Chemie, Universität Bielefeld, Germany, Universität Bielefeld = Bielefeld University, Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), and Brébion, Alice
- Subjects
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,[PHYS]Physics [physics] ,[CHIM.THEO] Chemical Sciences/Theoretical and/or physical chemistry ,MCTDH ,Vibronic couplings ,Quantum dynamics ,Molecular physics ,ComputingMilieux_MISCELLANEOUS ,[PHYS] Physics [physics] - Abstract
International audience
- Published
- 2010
26. Accounting for strong anharmonicity in Jahn-Teller and pseudo Jahn-Teller systems
- Author
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Eisfeld, Wolfgang, Viel, Alexandra, Theoretische Chemie, Universität Bielefeld, Germany, Universität Bielefeld = Bielefeld University, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Brébion, Alice, and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,[CHIM.THEO] Chemical Sciences/Theoretical and/or physical chemistry ,MCTDH ,Vibronic couplings ,Quantum dynamics ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 2008
27. Photoionization-induced dynamics of ammonia: potential energy surfaces and time-dependent wave packet studies
- Author
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Viel, Alexandra, Eisfeld, Wolfgang, Manthe, Uwe, Evenhuis, Christian, Neumann, Stefanie, Domcke, Wolfgang, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Theoretische Chemie, TU Munchen, Germany, Department of Chemistry, Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM)-Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM), Universität Bielefeld = Bielefeld University, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Theoretische Chemie, Universität Bielefeld, Germany, and Launay, Jean-Michel
- Subjects
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,[CHIM.THEO] Chemical Sciences/Theoretical and/or physical chemistry ,MCTDH ,Vibronic couplings ,[PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph] ,Quantum dynamics ,ComputingMilieux_MISCELLANEOUS ,[PHYS.PHYS.PHYS-CHEM-PH] Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph] - Abstract
International audience
- Published
- 2008
28. Photoionization-induced dynamics of the ammonia cation studied by wave packet calculations using curvilinear coordinates
- Author
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Alexandra Viel, Uwe Manthe, Wolfgang Eisfeld, Christian R. Evenhuis, Physique des atomes, lasers, molécules et surfaces (PALMS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Theoretische Chemie, Universität Bielefeld, Germany, Universität Bielefeld = Bielefeld University, and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)
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[PHYS]Physics [physics] ,Curvilinear coordinates ,Chemical Physics ,010304 chemical physics ,Chemistry ,Wave packet ,Anharmonicity ,Vibronic couplings ,General Physics and Astronomy ,Hartree ,Photoionization ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,MCTDH ,Normal mode ,Excited state ,0103 physical sciences ,Potential energy surface ,Physical and Theoretical Chemistry ,Atomic physics ,Quantum dynamics - Abstract
The determination of the photoelectron spectrum of NH3 and of the internal conversion dynamics of NH3+ recently published [A. Viel, W. Eisfeld, S. Neumann, W. Domcke, U. Manthe, J. Chem. Phys. 124 (2006) 214306] is complemented by the investigation of the effect of the vibrational angular momenta couplings on the dynamics. The multi-configurational time-dependent Hartree method is used to propagate a wave packet on the analytical anharmonic six-dimensional three-sheeted potential energy surface for the ground and first excited states of the ammonia cation. Curvilinear coordinates and the associated quasi-exact kinetic energy operator suitable for the multi-configurational time-dependent Hartree scheme are employed. A non-negligible effect of the use of Cartesian normal modes instead of the curvilinear coordinates is observed on the low energy part of the photoelectron spectrum. However, the three different time scales found in the dynamical calculations for the second absorption band are very similar regardless of the use of either normal modes or curvilinear coordinates. (C) 2007 Elsevier B.V. All rights reserved.
- Published
- 2008
29. Photoionization-induced dynamics of ammonia: Ab initio potential energy surfaces and time-dependent wave packet calculations for the ammonia cation
- Author
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Wolfgang Eisfeld, Alexandra Viel, Uwe Manthe, Wolfgang Domcke, Stefanie Neumann, Physique des atomes, lasers, molécules et surfaces (PALMS), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Theoretische Chemie, TU Munchen, Germany, Department of Chemistry, Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM)-Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM), Universität Bielefeld = Bielefeld University, Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), and Theoretische Chemie, Universität Bielefeld, Germany
- Subjects
Quantum dynamics ,Wave packet ,Ab initio ,General Physics and Astronomy ,010402 general chemistry ,01 natural sciences ,7. Clean energy ,MCTDH ,[PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph] ,Ab initio quantum chemistry methods ,0103 physical sciences ,Physics::Atomic and Molecular Clusters ,Physical and Theoretical Chemistry ,Physics::Chemical Physics ,010304 chemical physics ,Chemistry ,Vibronic couplings ,Multireference configuration interaction ,0104 chemical sciences ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,Excited state ,Potential energy surface ,Condensed Matter::Strongly Correlated Electrons ,Atomic physics ,Ground state - Abstract
An analytical anharmonic six-dimensional three-sheeted potential energy surface for the ground and first excited states of the ammonia cation has been developed which is tailored to model the ultrafast photoinduced dynamics. Selected ab initio cuts, obtained by multireference configuration interaction calculations, have been used to determine the parameters of a diabatic representation for this Jahn-Teller and pseudo-Jahn-Teller system. The model includes higher-order coupling terms both for the Jahn-Teller and for the pseudo-Jahn-Teller matrix elements. The relaxation to the ground state is possible via dynamical pseudo-Jahn-Teller couplings involving the asymmetric bending and stretching coordinates. The photoelectron spectrum of NH3 and the internal conversion dynamics of NH+3 have been determined by wave packet propagation calculations employing the multiconfigurational time-dependent Hartree method. Three different time scales are found in the dynamics calculations for the second absorption band. The ultrafast Jahn-Teller dynamics of the two excited states occurs on a 5 A time scale. The major part of the internal conversion to the ground state takes place within a short time scale of 20 fs. This fast internal conversion is, however, incomplete and the remaining excited state population does not decay completely even within 100 fs. (c) 2006 American Institute of Physics.
- Published
- 2006
30. Higher order (A+E)⊗e pseudo-Jahn–Teller coupling
- Author
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Alexandra Viel, Wolfgang Eisfeld, Theoretische Chemie, TU Munchen, Germany, Department of Chemistry, Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM)-Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM), Laboratoire de Physique Quantique (LPQ), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)
- Subjects
Coupling ,010304 chemical physics ,Chemistry ,Wave packet ,Jahn–Teller effect ,Quantum dynamics ,Degenerate energy levels ,Diabatic ,Vibronic couplings ,General Physics and Astronomy ,010402 general chemistry ,01 natural sciences ,Potential energy ,Symmetry (physics) ,0104 chemical sciences ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,[PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph] ,0103 physical sciences ,Physical and Theoretical Chemistry ,Atomic physics - Abstract
The pseudo-Jahn-Teller (PJT) coupling of a nondegenerate state A with a twofold degenerate state E by a degenerate vibrational mode e is studied for a general system with a C(3) main rotational axis. The PJT coupling terms up to sixth order are derived by symmetry considerations for this general (A+E) multiply sign in circle e case. The obtained expression for the 3 x 3 diabatic potential energy matrix is found to be closely related to the expression recently developed for the higher order Jahn-Teller case [A. Viel and W. Eisfeld, J. Chem. Phys. 120, 4603 (2004)]. The dynamical PJT coupling, which can arise for states of appropriate symmetry if one of the vibrational modes induces a change of the nuclear point group between D(3h), C(3v), C(3h), and C(3), is discussed. The effect of the higher order PJT coupling is tested by a two-dimensional model study based on the e bending mode of NH(3)(+). The models are analyzed by fitting the two-dimensional potential energy surfaces. The significance of the higher order terms on the nonadiabatic dynamics is demonstrated by quantum wave packet propagations.
- Published
- 2005
31. The sudden-polarization effect and its role in the ultrafast photochemistry of ethene
- Author
-
Uwe Manthe, Robert P. Krawczyk, Alexandra Viel, Wolfgang Domcke, Theoretische Chemie, TU Munchen, Germany, Department of Chemistry, and Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM)-Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM)
- Subjects
Materials science ,010304 chemical physics ,Vibronic couplings ,General Chemistry ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,MCTDH ,[PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph] ,0103 physical sciences ,Theoretical chemistry ,Quantum dynamics ,Polarization (electrochemistry) ,Molecular physics ,Ultrashort pulse ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 2003
32. Photoinduced dynamics of the valence states of ethene: A six-dimensional potential-energy surface of three electronic states with several conical intersections
- Author
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Wolfgang Domcke, Robert P. Krawczyk, Alexandra Viel, Uwe Manthe, Theoretische Chemie, TU Munchen, Germany, Department of Chemistry, and Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM)-Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM)
- Subjects
Valence (chemistry) ,010304 chemical physics ,Antisymmetric relation ,Chemistry ,Diabatic ,Ab initio ,Vibronic couplings ,General Physics and Astronomy ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,MCTDH ,[PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph] ,Ab initio quantum chemistry methods ,0103 physical sciences ,Potential energy surface ,Physics::Atomic and Molecular Clusters ,Physical and Theoretical Chemistry ,Coordinate space ,Atomic physics ,Quantum dynamics ,Analytic function - Abstract
International audience; A six-dimensional analytic potential-energy surface of the three valence states (N,V, Z) of ethene has been constructed on the basis of complete-active-space ab initio calculations and ab initio calculations with perturbation theory of second order based on a complete active reference space. The nuclear coordinate space is spanned by the torsion, the C–C stretch coordinate, the left and right pyramidalization and the symmetric and antisymmetric scissor coordinates. The C–H stretch coordinates and the CH2 rocking angles are kept frozen at their ground-state equilibrium value. A diabatic representation of the valence states of ethene has been constructed within the framework of a Hückel-type model. The diabatic potential-energy elements are represented as analytic functions of the relevant coordinates. The parameters of the analytic functions have been determined by a least-squares fit of the eigenvalues of the diabatic potential-energy matrix to the ab initio data for one-dimensional and two-dimensional cuts of the six-dimensional surface. As a function of the torsion, the analytic potential-energy surface describes the intersections of the V and Z states for torsional angles near 90°, which are converted into conical intersections by the antisymmetric scissor mode. As a function of pyramidalization of perpendicular ethene, it describes the intersections of the diabatic N and Z states, which are converted into conical intersections by displacements in the torsional mode. The analytic potential-energy surfaces can provide the basis for a quantum wave packet description of the internal conversion of photoexcited ethene to the electronic ground state via conical intersections.
- Published
- 2003
33. Excited-state electronic structure and time dependent wave-packet calculation on the photochemistry of ethylene
- Author
-
Viel, Alexandra, Theoretische Chemie, TU Munchen, Germany, Department of Chemistry, and Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM)-Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM)
- Subjects
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,MCTDH ,Vibronic couplings ,Quantum dynamics ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 2002
34. Energy transfer in bichromophoric molecules: the effect of symetry and donor/acceptor energy gap
- Author
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Yip, W. T., Levy, Donald H., Kobetić, Renata, and Piotrowiak, Piotr
- Subjects
Spiro-fluorene-phenanthrene ,Spiro-fluorene-naphtalene ,Vibronic couplings - Abstract
Fluorescence excitation spectra and single-vibronic-level emmission spectra of the model chromophores cyclopentaphenanthrene and 1, 8-dimethyl-naphtalene and the bichromphores spiro-fluorene-phenanthrene and spiro-fluorene-naphtalene are presented and analyzed.
- Published
- 1999
35. A Joint Theoretical and Experimental Study of the Behavior of the DIDS Inhibitor and its Derivatives.
- Author
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Jaunet-Lahary T, Goupille A, Jacquemin D, Fleury F, Graton J, and Laurent AD
- Subjects
- 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid analogs & derivatives, Isomerism, Models, Molecular, Protons, Quantum Theory, Spectrophotometry, Thermodynamics, 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid chemistry
- Abstract
4,4'-Diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) is a well-known ion-exchange inhibitor targeting cardiac functions and indirectly impeding both radio- and chemo-resistance. A joint computational and experimental study is presented to provide deeper insights into DIDS and other members of this family of compounds. To this end, we applied state-of-the-art density functional theory (DFT) and time-dependent DFT methods, in addition to measuring the optical properties. The experimental data show that such compounds are highly sensitive to their environment and that the optical properties change within as little time as 7 h. However, the optical properties of DIDS are similar in various acidic/basic environments, which were confirmed by pKa computations on both cis and trans isomers. The protonation analysis also highlights that the singly protonated form of DIDS behaves like a proton sponge compound. The experimentally observed redshift that can be seen when going from water to DMSO was reproduced solely by using the solvation model based on density, although the polarization continuum model and implicit/explicit hybrid schemes were also tested. The characteristic broadening of the absorption peak in water and the vibronic fine structure in DMSO were also reproduced thanks to vibronic coupling simulations associated with the solvent reorganization energy. For other stilbene derivatives, a correlation is found between the maximum absorption wavelength and the Hammett parameters., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2016
- Full Text
- View/download PDF
36. Study of the Franck-Condon and Herzberg-Teller Approximations
- Author
-
Lin, S. H. and Eyring, H.
- Published
- 1974
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