A5072933202- Advanced Chemical Physics Studies
- Atmospheric Ozone and Climate
- Astrophysics and Star Formation Studies
- Molecular Spectroscopy and Structure
- Spectroscopy and Laser Applications
- Atomic and Molecular Physics
- Quantum, superfluid, helium dynamics
- Molecular Junctions and Nanostructures
- Inorganic Fluorides and Related Compounds
- Atmospheric and Environmental Gas Dynamics
- Spectroscopy and Quantum Chemical Studies
- Atmospheric chemistry and aerosols
- Luminescence Properties of Advanced Materials
- Cold Atom Physics and Bose-Einstein Condensates
- Machine Learning in Materials Science
Tunis El Manar University
2010-2025
Tunis University
2006-2020
Context . The global context of making numerous data produced by researchers available requires collecting and organising the data, assigning meaningful metadata, presenting in a homogeneous way. BASECOL database, which collects inelastic rate coefficients for application to interstellar medium circumstellar cometary atmospheres, meets those requirements. Aims We aim present scientific content BASECOL2023 edition. Methods While previous versions relied on finding literature, current version...
Abstract Given its abundance in the interstellar medium recently justified by astronomical observations, chemistry and reactivity of metal-bearing molecule MgS require special attention. The availability up-to-date collision data between this most abundant perturbing species H2 He is an essential resource to derive reliable values molecular from observations. This work aims provide improved scattering parameters for system with He. A new two-dimensional potential energy surface (2D-PES)...
Abstract While the rotational spectroscopy of thiofulminic acid (HCNS), one isomers isothiocyanic (HNCS) is established, there no study its collisional excitation. In this work, we present first rate coefficients calculation newly observed HCNS(X1Σ+) colliding with He. To perform this, two-dimensional potential energy surface (2D-PES) calculated using explicitly correlated coupled cluster single, double and perturbative triple excitations [CCSD(T)-F12] method in conjunction aug-cc-pVTZ basis...
In astrochemistry, the carbenes c- and l-C<sub>3</sub>H<sub>2</sub> are lightest hydrocarbons to be detectable by rotational spectroscopy. We compute their interaction energy with helium atoms collisional quenching rates.
ABSTRACT Determining physical conditions in interstellar environments requires reliable estimation of collisional data for molecules detected space. In this work, we report a rate coefficients calculation MgC3N(X2Σ+) induced by collision with He. This study is based on new 2D potential energy surface (2D-PES), obtained from the explicitly correlated restricted open-shell coupled cluster approach single, double, and perturbative triple excitation (rccsd(t)-f12) aug-cc-pVTZ basis sets. The...
ABSTRACT To determine the chemical composition of gases in molecular clouds, oxygen-bearing systems CnO are needed as probe elements. The pentacarbon monoxide C5O was recently detected TMC-1, and order to derive accurate physical conditions from its rotational transitions, calculation rate coefficients C5O(1Σ+) induced by collision with He performed for thermal temperature below 100 K. These calculations based on a new 2D potential energy surface (2D-PES) obtained explicit correlated coupled...
ABSTRACT The C5S molecule is the largest member of series sulphur-containing carbon chains CnS observed in space. Given lack data concerning this molecule, we computed rate coefficients C5S(1Σ+) induced by collision with He. These rates are obtained for thermal temperature below 100 K mean a new two-dimensional potential energy surface (PES) calculated explicit correlated coupled cluster single, double, and pertubative triple excitation (ccsd(t)-f12) ab initio approach aug-cc-pVTZ basis...
Tricarbon monoxide (C3O) is an astrochemically important molecule. It a probe element for determining the chemical composition of gases in molecular clouds, as C3O major intermediate ion-molecule reactions gas phase. For C3O, no collision coefficients are available literature. To estimate abundance solar cold dark cloud: Taurus Molecular Cloud 1 (TMC-1) and find range cloud parameters, some authors used calculated values HC3N molecule, which isoelectronic has similar rotational constants....
An appropriate estimation of the abundance observed C5 radical in interstellar medium requires accurate radiative and collisional rate coefficients. We present first two-dimensional potential energy surface (2D-PES) for ground electronic state C5(X1Σ+)-He(X1S) van der Waals system, obtained using an explicitly correlated coupled-cluster method with single, double, perturbative triple excitations (RCCSD(T)-F12). This PES is subsequently used quantum close-coupling (CC) scattering...
The CCN radical has been recently detected in the interstellar medium. Accurate modeling of its abundance such media requires one to model excitation by both radiation and collisions. Here, we report first quantum mechanical close-coupling study CCN—He Calculations fine-structure resolved cross sections CCN(X2Π) induced collision with He are performed for kinetic energies below 500 cm−1. calculations based on new two-dimensional potential energy surfaces obtained from coupled cluster...
Abstract We have generated an ab initio three-dimensional potential energy surface (PES) for the state of LiSH. The spectroscopic data calculated from a full quartic force field are in very good agreement with values obtained microwave experiments. PES has been used to solve variationally nuclear motion problem and vibrational levels given up about 3500 cm−1 LiSH 2400 LiSD. For LiSH, anharmonic fundamental modes lie at 2571 (SH stretch), 578 (LiS stretch) 372 (LiSH bending), LiSD...
ABSTRACT To probe the physical conditions in molecular clouds, observations of rotational transitions a system are very important. Thus, accurate modelling emission spectra silicon carbides requires calculation collision rate coefficients for its systems. We determine here, collisional excitation SiC4 by He using new potential energy surface. The state-to-state between lower levels (j ≤ 28) calculated coupled-channel and coupled-state methods temperatures ranging from 5 to 300 K. Finally, we...
ABSTRACT For a better understanding of the physico-chemistry in interstellar medium, collisional data are needed. In this work, we provide rate coefficients for recently detected by Cabezas and collaborators 2023 sodium cyanoacetylide molecule NaC$_{3}$N($X^{1}\Sigma ^{+}$) induced collisions with He. A new two-dimensional potential energy surface (2D-PES) is derived adopting high-level theory explicitly correlated coupled cluster single, double, perturbative triple excitations (CCSD(T)-F12)...
We present quantum coupled-state calculations for the rotational excitation of interstellar propargylimine due to collisions with helium. The are based on new high-accurate three-dimensional potential energy surfaces (3D-PESs) adapted rigid-rotor scattering computations. two PESs (
ABSTRACT Collisional excitation of C5H+ by He was performed mean state-of-the-art methods. A high level theory quantum chemical calculations were made to determine the interaction potential energy surface with helium. The new two-dimensional obtained from RCCSD(T)-F12 ab initio approach associated aug-cc-pVTZ basis sets, presents two minima below its dissociation limit well depths $-101.8$ and $-100.2\, \mathrm{cm}^{-1}$ . In order derive accurate physical conditions rotational transitions...
Abstract Despite that the tricarbon monosulfide (C 3 S) is among first sulfur-containing carbon-chain molecules to be detected in interstellar medium, no studies focused on determination of its collisional rates. These rate coefficients are essential estimate abundance C S medium. Computations S( $^{1}\Sigma^{+}$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mi>Σ</mml:mi> <mml:none /> <mml:mo>+</mml:mo> <mml:mprescripts <mml:mn>1</mml:mn>...
Synopsis C 3 H 2 molecules are ubiquitous in the Galaxy and present important challenges their chemistry, whether cyclic or linear, possibly substituted with D. Obtaining theoretical rotational quenching rates by collisions He as projectiles is of great importance order to get quantitative abundance estimates. It all more challenging that many lines excited during collision, resulting computationnally very heavy quantum dynamics. The quality various approximations will be discussed, well for...
Abstract In order to derive accurate physical conditions of the interstellar clouds (like TMC-1) from rotational transitions C2O, collisional rates are needed. Based on a new two-dimensional potential energy surface (2D-PES), we report rate coefficients calculation C2O(X3Σ−) induced by collision with He. This PES was obtained explicitly correlated restricted open-shell coupled cluster single, double and perturbative triple excitation (rccsd(t)-f12) ab initio approach associated aug-cc-pVTZ...
The theoretical study of collisions between atoms and molecules provides a detailed description the involved mechanisms greatly contributes to improving atmospheric astrophysics models. In present paper, we focus on new calculation rate coefficients for first 25 rotational levels CaNC molecule in collision with He. A 2D potential energy surface (2D-PES), CaNC-He system, was determined using single, double perturbative triple excitation restricted coupled-cluster method [rccsd(t)] standard...
ABSTRACT Tricarbon and pentacarbon monoxides have been detected towards the Taurus Molecular Cloud (TMC-1) with relatively important abundances. Understanding chemical formation of these molecules requires interpreting their observational spectra by mean non-local thermodynamical equilibrium modelling. For this purpose, we report rate coefficients C3O C5O induced collision He for temperatures up to 100 K. These data are obtained calculating inelastic cross sections 31 low-lying rotational...