SCRIBANO Yohann
Fonction : Maître de conférences HDR
Organisme : UM2
Maître de Conférences
(HDR)
Thème de Recherche: Astrophysique Stellaire
yohann.scribano
umontpellier.fr
0467144535
Bureau: 7, Etg: 4, Bât: 21  Site : campus Triolet
Administration Nationale: 
Administration Locale: Responsable de formations
 Responsable de diplôme (M2)

Activités de Recherche: 
Théories et Simulations en Dynamique Quantique Moléculaire  Applications à l'Astrophysique Moléculaire 
Projets de Recherche: 
PI du projet ANR "HyTRAJ" (20202025) Partenaire du projet ANR "CROSS" (20222025) 
Domaines de Recherche:  Physique/Physique/Agrégats Moléculaires et Atomiques
 Physique/Physique/ChimiePhysique
 Physique/Physique/Physique Numérique

Dernieres productions scientifiques :


Vibrational frequency shift calculations of molecular hydrogen inside clathrate hydrates as a probe of intermolecular potentials
Auteur(s): Scribano Y.
(Séminaires)
Rutgers University, Physics Department (Newark, US), 20231027
Résumé: The study of small/medium size molecules inside nanoscale cavities of diverse host material, e.g.,
clathrates hydrates, cryogenic fuids (or superfuids), 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, . . . ). However the description of such systems is often far from
complete. Indeed, in such nanoscale con nement, the motion of the encapsulated molecule is far
from harmonic and is characterised by large amplitude motions. The translational centerofmass
motions of the caged molecules are quantized and strongly coupled to the molecular rotations,
which are quantized too., and also coupled to the internal vibrational motion of the guest molecule.
I will present a review on our recent progress in the development of e cient/accurate compu
tational methods for the rigorous quantum treatment of the intricate coupled translationrotation
dynamics of the molecular hydrogen in water clathrates. In particular, I will emphasize that our
methodology enables us to assess the impact of the condensedphase environment on the vibrational
frequency shift of the con ned molecule, and at the same time to probe the quality of intermolecular
potentials.



Rovibrational states calculations of the H$_2$O–HCN heterodimer with the Multiconfiguration Time Dependent Hartree method
Auteur(s): Tajouo teal Hervé, Quintassánchez Ernesto, Dubernet Marielise, Scribano Y., Dawes Richard, Gatti Fabien, Ndengué Steve
(Article) Publié:
Physical Chemistry Chemical Physics, vol. 25 p.31813–31824 (2023)
DOI: 10.1039/D3CP03225F
Résumé: Water and hydrogen cyanide are two of the most common species in space and the atmosphere
with the ability of binding to form dimers such as H$_2$O–HCN. In the literature, while calculations
characterizing various properties of the H$_2$O–HCN cluster (equilibrium distance, vibrational frequen
cies and rotational constants) have been done in the past, extensive calculations of the rovibrational
states of this system using a reliable quantum dynamical approach have yet to be reported. In
this work, we intend to mend that by performing the first calculation of the rovibrational states of
the H$_2$O–HCN van der Waals complex on a recently developed potential energy surface. We use
the Block Improved Relaxation procedure implemented in the Heidelberg MultiConfiguration Time
Dependent Hartree (MCTDH) package to compute the states of the H$_2$O–HCN isomer, from which
we extract the transition frequencies and rotational constants of the complex. We further adapt
an approach first suggested by Wang and Carrington—and supported here by analysis routines of
the Heidelberg MCTDH package—to properly characterize the computed rovibrational states. The
subsequent assignment of rovibrational states was done by theoretical analysis and visual inspection
of the wavefunctions. Our simulations provide a Zero Point Energy (ZPE) and intermolecular vibra
tional frequencies in good agreement with past ab initio calculations. The transition frequencies and
rotational constants obtained from our simulations match well with the available experimental data.
This work has the broad aim to propose the MCTDH approach as a reliable option to compute and
characterize rovibrational states of van der Waals complexes such as the current one.



Machine learning prediction of statetostate rate constants for astrochemistry
Auteur(s): Bossion D., Nyman Gunnar, Scribano Y.
(Article) Publié:
Artificial Intelligence Chemistry, vol. 2 p.xxx (2024)
DOI: 10.1016/j.aichem.2024.100052
Résumé: We investigate the possibility to use an artificial neural network in order to generate a large number of accurate statetostate rate constants, from the available rates obtained at different accuracy levels, including small numbers of accurate rates and large numbers of lowaccuracy rates.



Coping with the node problem in resonant scattering simulations using quantum trajectories: an efficient and accurate combined analyticalnumerical scheme
Auteur(s): Dupuy L., Scribano Y.
(Article) Publié:
The European Physical Journal. Special Topics, vol. 232 p.1871–1883 (2023)
DOI: 10.1140/epjs/s11734023009243
Résumé: We report an efficient approach to accurately and efficiently compute transmission probabilities in
resonant deep tunneling regime. Dynamical systems subjects to this phenomenon prove hard to
simulate numerically even with exact methods, which motivates new methodological developments
owing to the impact resonant phenomena have in several processes such as chemical reactions and
electronic transport. Our approach is based on the original reformulation of stationnary quantum
scattering as the propagation of a quantum trajectory in extended phase space. The present paper
discusses in detail the node problem occurring to the timeindependent quantum trajectory method
in this very challenging situation, and introduces an efficient nodeskipping scheme to circumvent
expensive numerical integration in their vicinity. We illustrate how this numerical extension allows
to treat all regimes of quantum tunneling with great versatility by comparison to existing approaches
of the litterature. The quantum trajectory thus represents a very promising tool for the study of
complex chemical reactions characterized by resonant tunneling effect.



Making sense of transmission resonances and Smith lifetimes in onedimensional scattering: the extended phase space quantum trajectory picture
Auteur(s): Dupuy L., Parlant Gerard, Poirier Bill, Scribano Y.
(Article) Publié:
Chemical Physics, vol. 572 p.111952 (2023)
DOI: 10.1016/j.chemphys.2023.111952
Résumé: Resonances are ubiquitous in a wide range of physical and chemical phenomena. Their impact on
quantum scattering processes renders their study as important as it can be puzzling. In this paper,
we illustrate the accuracy of a fully quantum, purely trajectory based reformulation of quantum
mechanics proposed by one of the authors (Poirier) to acquire insights on shape resonances through
direct and accurate computation of the diagonal elements of Smith’s lifetime matrix. This study also
generalizes the relationship between the quantum trajectory propagation time and the Eisenbud
Wigner time delay—introduced in our previous publication[1] for symmetric potentials—to the
general case of asymmetric potential profiles. In addition, we show how the complex amplitudes of
the scattering matrix can be extracted from left and rightincident quantum trajectories. Finally, we
demonstrate that extended phase space quantum trajectories not only recover Smatrix and quantum
time quantities, but they also provide their own picture of resonant phenomena, as dynamically
distinct events characterised by an integer number of closed orbits in the quantum phase space.

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