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30 results on '"Scribano, Yohann"'

1. Smolyak representations with absorbing boundary conditions for reaction path Hamiltonian of reactive scattering

Author

Scribano, Yohann, Dupuy, Lucien, Lauvergnat, David, and Clementin, Nicolas

Subjects
[PHYS.PHYS.PHYS-COMP-PH] Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], [PHYS.PHYS.PHYS-ATM-PH] Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], [PHYS.PHYS.PHYS-CHEM-PH] Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract

In this work, we present the efficient combination of Smolyak representations with time independent quantum mechanical approach using absorbing boundary conditions for the cumulative reaction probability calculations of a multidimensional reactive scattering problem. Our approach uses both kinds of Smolyak representations (finite basis and grid) which drastically reduces the size of the basis representation for the cumulative reaction operator. The cumulative reaction probability is thus obtained by solving the eigenvalue problem within the context of reaction path Hamiltonian using the compact Smolyak basis combined with an iterative Lanczos algorithm. Benchmark calculations are presented for reactive scattering models with a linear reaction coordinate and applied to a 25D model highlighting the efficiency of the present approach for multidimensional reactive processes.

Published
2022

2. Quantum mechanical calculations of cumulative reaction probabilities using an efficient Smolyak scheme

Author

DUPUY, Lucien, SCRIBANO, Yohann, Lauvergnat, David, Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie Physique (ICP), and Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract

Cumulative reaction probability plays a central role in the calculation of reaction rate constant of any bimolecular chemical reaction of interest. In order to give meaningful results, these calculations should be performed for chemical systems with a large number of degrees of freedom leadingto expensive and often infeasible simulations. In this work, a new computational scheme is proposed to allow high dimensional quantum reactive simulations. This scheme is based on the Green’s function operator technics combined to absorbing boundary conditions, a powerful approach introduced by W.H. Miller, T. Seideman and U. Manthe many years ago [1,2]. The new implementation takes benefit that the initial quantum reactive scattering problem can be cast into an eigenvalue problem [2] and uses the high efficiency and accuracy of Smolyak algorithm [3] to build very compact basis for eigenvalue problems [4]. Using this new computational framework, it is now possible to perform quantum dynamics simulations for multidimensional systems pushing away the curse of dimensionality problem. Some preliminary results will be presented [5] using this new powerful scheme

Published
2020

3. Quantum dynamics with trajectories: one-dimensional scattering problems

Author

DUPUY, Lucien, SCRIBANO, Yohann, Laboratoire Univers et Particules de Montpellier (LUPM), and Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract

National audience; We present recent progress on quantum trajectories method for one dimensional resonant reactive scattering processes.

Published
2020

4. Dynamics of H + HeH$^+ (v=0,j=0) \rightarrow$ H$_2^+$ + He: Insight on the Possible Complex-Forming Behaviour of the Reaction

Author

Gonzalez-lezana, Tomas, BOSSION, Duncan, SCRIBANO, Yohann, Bhowmick, Somnath, Suleimanov, Yury, Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Laboratoire Univers et Particules de Montpellier (LUPM), Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), The Cyprus Institute, Massachusetts Institute of Technology (MIT), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), and Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry
Abstract

International audience; The H + HeH$^+ (v=0,j=0) \rightarrow$ H$_2^+$ + He reaction has been studied by means of a combination of theoretical approaches: a statistical quantum method (SQM), ring polymer molecular dynamics (RPMD), and the quasiclassical trajectory (QCT) method.

Published
2019

5. Impact of the condensed-phase environment on the quantum dynamics of a hydrogen molecule in clathrate hydrates

Author

SCRIBANO, Yohann, Lauvergnat, David, Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie Physique D'Orsay (LCPO), and Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract

The study of small/medium size molecules inside nanoscale cavities of diverse host material, e.g.,clathrates hydrates, cryogenic fluids (or superfluids), fullerenes, carbon nanotubes and zeolites, has receiveda great deal of attention over the past years due to their broad application domain (condensed matter physics,nanomaterial sciences, geoscience, quantum chemistry, astrophysical and planetary sciences, biophysics, ...).However the description of such systems is often far from complete. Indeed,in such nanoscale confinement, the motion of the encapsulated molecule is far from harmonic and is characterised by large amplitude motions. The translational center-of-mass motionsof the caged molecules are quantized and strongly coupled to themolecular rotations, which are quantized too.In this talk, I will present our recent progress in the Translation-Rotation (TR) and Vibration-Translation-Rotation (VRT) bound states calculation of guest molecules such as molecular hydrogen in a clathrate hydrate. Within this study, we have investigated the effect of a non-rigid description of a clathrate hydrate framework on the encapsulated molecular hydrogen eigenstates using an efficient sparse grid scheme which allow us to consider up to 65 degrees of freedom. Traditionally, the water cage structure is assumed to be rigid, thus ignoring the quantum nature of hydrogen nuclei in the water framework.

Published
2019

6. Strategies for high dimensional quantum dynamics

Author

SCRIBANO, Yohann, Lauvergnat, David, Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie Physique D'Orsay (LCPO), and Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract

International audience; I present some recent work using sparse-grid technics for high dimensional molecular bound states calculations

Published
2019

7. Extending vibrational configuration interaction methods for high dimensional anharmonic vibrational spectrum calculations

Author

SCRIBANO, Yohann, Benoit, David, Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and University of Hull [United Kingdom]

Subjects
[PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract

we present new strategy to perform vibrational mean field and vibrational configuration interaction coalculations for large molecular systems. Thanks to an efficient pruning scheme based on the many body expansion of the potential energy surface, we show that variational bound state calculation is possible form large molecular systems

Published
2019

8. Sparse grid methods for high dimensional quantum molecular dynamics with large amplitude motions

Author

SCRIBANO, Yohann, Lauvergnat, David, Dupuy, Lucien, Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie Physique D'Orsay (LCPO), Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Stellaire, and Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract

International audience; I present the recent results obtained for high dimensional eigenvalue problems involving large amplitude motions as ones meet in molecular spectroscopy and reaction dynmics

Published
2019

9. Statistical behaviour of the HeH$^+$ + H $\rightarrow$ H$_2^+$ + He reaction, a quasi-classical and quantum statistical study

Author

BOSSION, Duncan, SCRIBANO, Yohann, Gonzalez lezana, Tomas, Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Instituto de Física Fundamental [Madrid] (IFF), and Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)

Subjects
[PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract

National audience; Result of statistical quanum physics method, quasi-classical trajectories and ring polymer molecular dynamics (RPMD) to study the statistical behaviour and reliability of RPMD methodology for insertion reactions.

Published
2019

10. Suitable sparse grid scheme for the calculation of the vibration-translation-rotation eigenstates of confined molecular system

Author

SCRIBANO, Yohann, Laboratoire Univers et Particules de Montpellier (LUPM), and Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract

International audience; The quantum dynamics studies of molecular bound states are actually limited by the well known dimensionality problem. Indeed even for molecules of medium size, usual quadrature techniques have already reached their limit since a multidimensional direct-product grid can be very large. An alternative to avoid the direct-product grid is to use the Smolyak sparse-grid techniques, recently investigated by Avila and Carrington [1] for the calculation of vibrational bound states of semi-rigid molecules. Lauvergnat and Nauts [2] have proposed a new implementation of such sparse grid for the study of the torsional levels of methanol in full dimensionality in order to treat one large amplitude motion. The efficiency of this kind of grid is related to the substitution of a single large direct-product grid by a sum of small direct-product grids. We will present a recent adaptation of this kind of sparse grid scheme for the calculation of six-dimensional (6D) vibration-translation-rotation bound states of confined molecule such as H$_2$ (and its isotopologues) in water clathrate [3]. In particular, we are able to use a combination of 2D-grids associated to spherical harmonic basis functions and the usual 1D-gaussian quadrature grids to form the Smolyak sparse-grid [4]. We will discuss the efficiency of this approach for the calculation the intramolecular vibrational shift of H$_2$ as well as the effect of the condensed phase environment.[1] A. Avila and T. Carrington, J. Chem. Phys. 131 (2009), 174103.[2] D. Lauvergnat and A. Nauts, Spectrochim. Acta. Part A 119 (2014), 18.[3] D. Lauvergnat and P. Felker and Y. Scribano and D. Benoit and Z. Bacic, J. Chem. Phys.150 (2019), 154303.[4] A. Powers and Y. Scribano and D. Lauvergnat and E. Mebe and D. Benoit and Z. Bacic, J.Chem. Phys. 148 (2018), 144304.

Published
2019

11. Simulations numériques de systèmes hamiltonien astrophysiques : collisions atome-molécule et orbites stellaires

Author

BOSSION, Duncan, SCRIBANO, Yohann, Wozniak, Herve, Laboratoire Univers et Particules de Montpellier (LUPM), and Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2)

Subjects
[PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], [PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph]
Abstract

National audience; Présentation de l'utilisation du centre de calcul pour les simulations numériques de systèmes hamiltoniens astrophysiques.

Published
2018

12. Collisional excitation of H$_2$ at high temperatures

Author

BOSSION, Duncan, SCRIBANO, Yohann, Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2)

Subjects
[PHYS]Physics [physics], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2018

13. Ro-vibrational excitation of H$_2$ by H for high temperature regime

Author

BOSSION, Duncan, SCRIBANO, Yohann, Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2)

Subjects
[PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract

International audience; Presentation of the results of the study of the H + H$_2$ reaction for high temperatures using quasi-classical trajectory method, comparison with accurate time-independent quantum method at lower temperature.

Published
2018

14. Collisional excitation of H$_2$ by H atoms at high temperature for astrophysical applications

Author

BOSSION, Duncan, SCRIBANO, Yohann, Laboratoire Univers et Particules de Montpellier (LUPM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), and Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS]Physics [physics], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2018

15. Adiabatic quantum trajectory capture for cold and ultra-cold chemical reactions

Author

SCRIBANO, Yohann, Parlant, Gerard, Poirier, Bill, Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), and Texas Tech University [Lubbock] (TTU)

Subjects
[PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract

International audience; The Langevin capture model is often used to describe barrierless reactive collisions. At very lowtemperatures, quantum effects may alter this simple capture image and dramatically affect the reactionprobability. In this paper, we use the trajectory-ensemble reformulation of quantum mechanics, asrecently proposed by one of the authors (Poirier) to compute adiabatic-channel capture probabilitiesand cross-sections for the highly exothermic reaction Li + CaH(v = 0, j = 0)!LiH + Ca, at low andultra-lowtemperatures. Each captured quantum trajectory takes full account of tunneling and quantumreflection along the radial collision coordinate. Our approach is found to be very fast and accurate,down to extremely low temperatures. Moreover, it provides an intuitive and practical procedurefor determining the capture distance (i.e., where the capture probability is evaluated), which wouldotherwise be arbitrary.

Published
2018

16. Quasi-classical and quantum study of atom-diatom collisions for high temperature regime

Author

BOSSION, Duncan, SCRIBANO, Yohann, Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2)

Subjects
[PHYS]Physics [physics], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], ComputingMilieux_MISCELLANEOUS
Abstract

National audience

Published
2018

17. Adiabatic quantum trajectory capture method for cold and ultra-cold chemical reactions

Author

SCRIBANO, Yohann, Parlant, Gerard, Poirier, Bill, Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Texas Tech University [Lubbock] (TTU), and Clementin, Nicolas

Subjects
[PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-COMP-PH] Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], [PHYS.PHYS.PHYS-ATM-PH] Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], [PHYS.QPHY] Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-CHEM-PH] Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract

While direct reactions with activation barriers are now routinely calculated, reactions going through a longlivedintermediate complex are much more difficult to study[1, 2]. Complex-forming reactions are often barrierlessand are thus relevant to the field of cold and utra-cold chemistry [2]. With decreasing temperature, wave effectsbecome increasingly important and may dominate the collisional behavior at ultralow temperatures. Capture theories(close-coupling expansion with boundary conditions applied in the reactant channel) are often used to studycomplex-forming reactions [3, 4].The Langevin capture model is often used to describe barrierless reactive collisions. At very low temperature,quantum effects may alter this simple capture image and dramatically affect the reaction probability. In this talk,we use the trajectory-ensemble reformulation of quantum mechanics without wavefunctions recently proposed byPoirier and coworkers[5, 6] to compute adiabatic-channel capture probabilities and cross-sections for the reactionLi + CaH(v = 0; j = 0)!LiH + Ca at low and ultra-low temperatures. The captured quantum trajectory takes fullaccount of tunneling and quantum reflection along the radial collision coordinate. Our approach turns out to bevery fast and accurate, down to extremely low temperatures.

Published
2018

18. An efficient sparse-grid scheme for the quantum dynamics of confined molecular hydrogen

Author

SCRIBANO, Yohann, Lauvergnat, David, Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), AS, Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie Physique D'Orsay (LCPO), and Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract

International audience; The study of small/medium size molecules inside nanoscale cavities of diverse host material, e.g., clathrates hydrates, cryogenic fluids (or superfluids), fullerenes, carbon nanotubes and zeolites, has received a great deal of attention over the past years due to their broad application domain (condensed matter physics, nanomaterial sciences, geoscience, quantum chemistry, astrophysical and planetary sciences, biophysics, \ldots).However the description of such systems is often far from complete. Indeed, in such nanoscale confinement, the translational center-of-mass motions of the caged molecules are quantized and strongly coupled to the molecular rotations, which are quantized too. To interpret experimental data, theoretical tools are useful but we need to go beyond the simple harmonic approximation as the guest molecule presents very large amplitude motions (translation and rotation) and its interaction with the nanoscale cavity can be far from harmonic. A rigorous quantum treatment of the intricate coupled translation-rotation (TR) dynamics of the caged diatomic molecules is far from a routine task.In this talk, I will present recent methodological development based on the concept of Smolyak sparse grid technic for the rigorous quantum treatment of the intricate coupled translation-rotation (TR) dynamics of the molecular hydrogen in water clathrates.

Published
2018

19. Simulations numériques des collisions atome-molécule pour l'astrophysique

Author

BOSSION, Duncan, SCRIBANO, Yohann, Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2)

Subjects
[PHYS]Physics [physics], [PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], ComputingMilieux_MISCELLANEOUS
Abstract

National audience

Published
2018

20. State-to-state study of the D+H$_2$ reaction for the primordial Universe

Author

BOSSION, Duncan, SCRIBANO, Yohann, Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2)

Subjects
[PHYS]Physics [physics], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], ComputingMilieux_MISCELLANEOUS
Abstract

National audience

Published
2017

21. Adiabatic model for molecule-para H$_2$ dynamics and spectroscopy

Author

SCRIBANO, Yohann, Faure, Alexandre, Laboratoire Univers et Particules de Montpellier (LUPM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), and Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract

International audience; The Time Independant Quantum Method is the reference for the calculations of cold molecule-molecule collisions. This close-coupling (CC) approach is commonly used in the cold chemistry and molecular astrophysics communities. However, the numerical cost of the CC-method increases significantlywith the size of the target molecule and some new methods should be investigated. I will present the use of an adiabatic model (and its possible extension) in the context of the CC-method. I will present the results (inelastic cross sections and rate constants) for the water colliding with para-Hydrogen molecule. The internal rotational adiabatic decoupling scheme reduces dimensional dynamics from a 5D to a 3D problem and a good agreement is found between those two calcutaions. This adiabatic reduction of dimensionality seems very promising for scattering studies involving the excitation of a heavy target molecule by a light molecular projectile.

Published
2017

22. A Smolyak sparse-grid scheme for the quantum dynamics of confined molecular hydrogen

Author

SCRIBANO, Yohann, Lauvergnat, David, Laboratoire Univers et Particules de Montpellier (LUPM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Laboratoire de Chimie Physique D'Orsay (LCPO), and Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract

International audience; We present in this talk the efficiency of the smolyak sparse grids for the desciption of molecular large amplitude motion. The method is applied to the calculation of the coupled translation-rotation eigenstates of H2 in water clathrate.

Published
2017

23. Coupled translation-rotation bound states of molecular hydrogen in clathrate hydrates from first principles

Author

SCRIBANO, Yohann, Lauvergnat, David, Laboratoire Univers et Particules de Montpellier (LUPM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Laboratoire de Chimie Physique D'Orsay (LCPO), and Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract

The study of small/medium size molecules inside nanoscale cavities of diverse host material, e.g.,clathrates hydrates, cryogenic fluids (or superfluids), fullerenes, carbon nanotubes and zeolites, has receiveda great deal of attention over the past years due to their broad application domain (condensed matter physics,nanomaterial sciences, geoscience, quantum chemistry, astrophysical and planetary sciences, biophysics, ...).However the description of such systems is often far from complete. Indeed,in such nanoscale confinement, the translational center-of-mass motionsof the caged molecules are quantized and strongly coupled to themolecular rotations, which are quantized too. To interpret experimentaldata, theoretical tools are useful but we need to go beyond the simple harmonicapproximation as the guest molecule presents very large amplitudemotions (translation and rotation) and its interaction with the nanoscalecavity can be far from harmonic. A rigorous quantum treatment of the intricatecoupled translation-rotation (TR) dynamics of the caged diatomicmolecules is far from a routine task.

Published
2017

24. Quantum trajectory approach to chemical reaction dynamics: Application to the capture process

Author

Scribano, Yohann, Parlant, Gerard, Laboratoire Univers et Particules de Montpellier (LUPM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), AS, Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), and Clementin, Nicolas

Subjects
[PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-COMP-PH] Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], [PHYS.PHYS.PHYS-ATM-PH] Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], [PHYS.QPHY] Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-CHEM-PH] Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract

National audience; In this contribution, we expose a new mixed quantum-classical reaction dynamics method whosenovelty is that it is entirely based on trajectories. Our approach rests on the concept of quantumtrajectory, which has been long been considered a philosophical and interpretative tool for quantummechanics [1]. Recently, quantum trajectories have been “rediscovered” with the goal of developinga totally new and unconventional computational method for doing quantum reaction dynamics [2,3].The most recent formulation, due to Bill Poirier and coworkers [4-6], sums up as a system ofcoupled ordinary differential equations (ODEs), that can be propagated in an extremely stable andaccurate manner. Potential advantages of this method are easily seen: (i) accurate propagation canbe extended to very large internuclear distances at low temperature; (ii) the propagation of onequantum degree of freedom together with several—possibly many—classical degrees of freedomsimply amounts to solving a “cheap” classical-like ODE system.Here we elaborate on our companion communication “Quantum trajectory capture at low and ultralowtemperature”. The above quantum trajectory approach is introduced and its physical as well ascomputational advantages are detailed, with special emphasis on the capture process.

Published
2015

25. Quantum trajectory capture for complex-forming reactions

Author

SCRIBANO, Yohann, Parlant, Gerard, Clementin, Nicolas, Laboratoire Univers et Particules de Montpellier (LUPM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), and CTMM

Subjects
[PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.QPHY] Physics [physics]/Quantum Physics [quant-ph]
Abstract

International audience; While direct reactions with activation barriers are now routinely calculated, reactions going through a longlivedintermediate complex are much more difficult to study[1, 2]. Complex-forming reactions are often barrierlessand are thus relevant to the field of cold and utra-cold chemistry [2]. With decreasing temperature, wave effectsbecome increasingly important and may dominate the collisional behavior at ultralow temperatures.Capture theories (close-coupling expansion with boundary conditions applied in the reactant channel) are oftenused to study complex-forming reactions [3, 4]. In this contribution we propose a new approach that describes thecapture process by evolving quantum trajectories in the reactant channel up to a given limit inside the centrifugalbarrier. The quantum trajectories take full account of quantum effects [5] along the reaction path direction. Inparticular, tunneling effects, which can change the reaction rate by orders of magnitude, are accurately computed.Apart from the entrance channel motion, which is guided by quantum trajectories, all other coordinates aretreated classically [6]. Our trajectory method is thus highly "classical-like" [6]. It is aimed at large system reactionswith quantum effects, still out of reach for current quantum scattering codes. Preliminary results will be presentedat the conference.References[1] H. Guo, Rev. Phys. Chem. 31, 1 (2012).[2] M. T. Bell, and T. P. Softley, Mol. Phys. 99, 107 (2009).[3] D.C. Clary and J.P. Henshaw, Faraday Discuss. Chem. Soc. 84, 333 (1987).[4] E.J. Rackham, T. Gonzalez-Lezana, and D.E. Manolopoulos, J. Chem. Phys. 119, 12895 (2003).[5] B. Poirier, Chem. Phys. 370, 4 (2010).[6] G. Parlant, Y.-C. Ou, K. Park, and B. Poirier, Comp. Theor. Chem. 990, 3 (2012).

Published
2015

26. Quantum trajectory capture at low and ultra-low temperature

Author

SCRIBANO, Yohann, Parlant, Gerard, Clementin, Nicolas, Laboratoire Univers et Particules de Montpellier (LUPM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), AS, Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), and Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)

Subjects
[PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], [PHYS.PHYS.PHYS-COMP-PH] Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], [PHYS.PHYS.PHYS-ATM-PH] Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], [PHYS.QPHY] Physics [physics]/Quantum Physics [quant-ph], [PHYS.PHYS.PHYS-CHEM-PH] Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract

National audience; The classical capture model for chemical reactions assumes that all trajectories with enough energyto cross the (centrifugal) barrier in the effective potential actually do so, and then proceed to formthe products. However, wave effects (not accounted for in a classical approach, by definition)become increasingly important with decreasing temperature and may dominate the collisionalbehavior at ultra-low temperatures.In this contribution we propose a new approach that describes the capture process by evolvingquantum trajectories [1,2] in the reactant channel up to a given limit, the capture distance, on theinside of the centrifugal barrier. The quantum trajectories take full account of quantum effects alongthe reaction path direction in the entrance channel. In particular, tunneling and quantum reflection,which can change the reaction rate by orders of magnitude, are accurately computed. In addition,quantum trajectories give valuable physical insight into the quantum capture process all along theapproach of the reactants. They also provide a technical means to determine the optimum capturedistance.Moreover, quantum trajectories along the reactant approach can easily be coupled with classicaltrajectories that drive the rest of the degrees of freedom of the system [3]. Apart from the captureprocess, which is guided by a quantum trajectory, all other coordinates are treated classically [3].This mixed quantum-classical capture approach is thus highly “classical-like” [3] and is aimed atlarge system reactions with quantum effects, still out of reach for current quantum scattering codes.Preliminary results will be presented at the conference.The authors are very grateful to Bill Poirier for his ongoing encouragement.[1] B. Poirier, “Bohmian mechanics without pilot waves”, Chem. Phys. 370, 4 (2010)[2] J. Schiff and B. Poirier, “Quantum mechanics without wavefunctions”, J. Chem. Phys. 136

Published
2015

27. Quantum dynamics study of rate constant for a reactive collision of astrophysical interest : the D+ + H2 reaction

Author

SCRIBANO, Yohann, Gonzalez lezana, Tomas, Honvault, P., Laboratoire Univers et Particules de Montpellier ( LUPM ), Université Montpellier 2 - Sciences et Techniques ( UM2 ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Université de Montpellier ( UM ) -Centre National de la Recherche Scientifique ( CNRS ), Instituto de Física Fundamental [Madrid] ( IFF ), Consejo Superior de Investigaciones Científicas [Spain] ( CSIC ), Laboratoire Interdisciplinaire Carnot de Bourgogne ( LICB ), Université de Bourgogne ( UB ) -Centre National de la Recherche Scientifique ( CNRS ), Clementin, Nicolas, Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Instituto de Física Fundamental [Madrid] (IFF), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Laboratoire Interdisciplinaire Carnot de Bourgogne (LICB), and Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [ PHYS.QPHY ] Physics [physics]/Quantum Physics [quant-ph], [PHYS.QPHY] Physics [physics]/Quantum Physics [quant-ph]
Abstract

For chemistry networks describing the reactions for the early universe and especially for accuratemodels of the enrichment of deuterated molecules observed, we need to know in detail manystate-to-state rate coeffcients. Today most of the rate coeffcients of interesting reactions are stillunknown or with a poor accuracy. For example, the uncertainty about the rate coeffcient for thereaction directly affects model predictions for the HD abundance and thereby the cooling rate ofthe primordial gas. It is therefore of astrophysical importance to determine an accurate value ofthese rates, and helping to understand the cooling requires a complete set of the state-to-state ratecoefficients as well as the total rate coefficient.In this talk, I will present the Time Independent Quantum Mechanical (TIQM)and Statistical Quantum Mechanical (SQM) results for the D++H2 reaction at low temperatureusing an accurate ab initio potential. The state to state cross sections at low collisional energiesand rate coefficients at low temperature have been computed and are compared to the availableexperimental data.

Published
2014

29. Quantum dynamics study of the D$^+$ + H$_2$ reaction at low temperature

Author

SCRIBANO , Yohann, Gonzalez-lezana , Tomas, Honvault , Pascal, Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Laboratoire Interdisciplinaire Carnot de Bourgogne (LICB), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), Quantum Reactive Scattering (XII th), Laboratoire Univers et Particules de Montpellier ( LUPM ), Université Montpellier 2 - Sciences et Techniques ( UM2 ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Université de Montpellier ( UM ) -Centre National de la Recherche Scientifique ( CNRS ), Consejo Superior de Investigaciones Científicas [Spain] ( CSIC ), Laboratoire Interdisciplinaire Carnot de Bourgogne ( LICB ), Université de Bourgogne ( UB ) -Centre National de la Recherche Scientifique ( CNRS ), and Clementin, Nicolas

Subjects
[ PHYS.QPHY ] Physics [physics]/Quantum Physics [quant-ph], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], education, [PHYS.QPHY] Physics [physics]/Quantum Physics [quant-ph]
Abstract

International audience; For chemistry networks describing the reactions for the early universe and especially for accurate models of the enrichment of deuterated molecules observed, we need to know in detail many state-to-state rate coefficients. For instance, Glover and Abel [1] modeled the chemistry of H2 and HD primordial gas using a chemical network consisting of 115 reactions between 16 species. Today most of the rate coefficients of interesting reactions are still unknown or with a poor accuracy. For example, the uncertainty about the rate coefficient for the reaction D+ + H2 --> HD + H+ directly affects model predictions for the HD abundance and thereby the cooling rate of the primordial gas. It is therefore of astrophysical importance to determine an accurate value of these rates, and helping to understand the cooling requires a complete set of the state-to-state rate coefficients as well as the total rate coefficient.We have thus studied the reaction with Time Independent Quantum Mechanical (TIQM) and Statistical Quantum Mechanical (SQM) methods and using the recent potential energy surface of Velilla et al. determined for H3+ [2]. The state to state cross sections at low collisional energies and rate coefficients at low temperature have been computed and are compared to the available experimental data [3,4]. The TIQM results are also compared with the SQM results for this low energy regime [5].[1] Glover S.C. O., Abel T., Mon. Not. R. Astron. Soc. , 2008, 388, 1627. [2] Velilla L. et al., J. Chem. Phys. A , 2008, 129, 084307.[3] Honvault P. and Scribano Y., J. Phys. Chem. A , 2013, in press. (DOI: 10.1021/jp3124549).[4] Gerlich D. and Schlemmer S., Planet. Space Sci. , 2002, 50, 1287.[5] Gonzalez Lezana T., Honvault P. and Scribano Y., submitted to J. Chem. Phys.

Published
2013

30. Rotational excitation of mono- and doubly-deuterated water by hydrogen molecules

Author

Faure, A., Wiesenfeld, Laurent, Scribano, Yohann, Ceccarelli, C., Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interdisciplinaire Carnot de Bourgogne (LICB), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble ( IPAG ), Observatoire des Sciences de l'Univers de Grenoble ( OSUG ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ) -Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Interdisciplinaire Carnot de Bourgogne ( LICB ), and Université de Bourgogne ( UB ) -Centre National de la Recherche Scientifique ( CNRS )

Subjects
ENERGY, H-2, [SDU]Sciences of the Universe [physics], HERSCHEL OBSERVATIONS, H2O, INTERSTELLAR HEAVY-WATER, TEMPERATURE, SPECTRAL SURVEYS, HDO
Abstract

International audience; Rate coefficients for rotational transitions in HDO and D2O induced by H-2 collisions below 300 K are presented. Calculations have been performed at the close-coupling and coupled-states levels with the deuterated variants of the H2O-H-2 interaction potential of Valiron et al. The HDO-H-2 and D2O-H-2 rate coefficients are compared to the corresponding rate coefficients for HDO-He and H2O-H-2, respectively. Significant differences are observed. In particular the new HDO rate coefficients are found to be significantly larger (by up to three orders of magnitude) than the corresponding HDO-He rate coefficients. The impact of the new HDO rate coefficients is examined with the help of non-LTE radiative transfer calculations. A number of potential HDO maser lines are finally identified, in particular the 80.6 GHz (1(1,0)-1(1,1)) transition.

Published
2012

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