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Related papers: Inelastic processes in strontium-hydrogen collisio…

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Rate coefficients for inelastic Na+H collisions are calculated for all transitions between the ten levels up to and including the ionic state (ion-pair production), namely Na(3s,3p,4s,3d,4p,5s,4d,4f,5p)+H(1s) and Na+ + H-. The calculations…

Solar and Stellar Astrophysics · Physics 2015-05-19 P. S. Barklem , A. K. Belyaev , A. S. Dickinson , F. X. Gadea

Rate coefficients for inelastic Mg+H collisions are calculated for all transitions between the lowest seven levels and the ionic state (charge transfer). The rate coefficients are based on cross-sections from full quantum scattering…

Solar and Stellar Astrophysics · Physics 2015-06-04 P. S. Barklem , A. K. Belyaev , A. Spielfiedel , M. Guitou , N. Feautrier

We performed the non-local thermodynamic equilibrium (non-LTE) calculations for Ti I-II with the updated model atom that includes quantum-mechanical rate coefficients for inelastic collisions with hydrogen atoms. We have calculated for the…

Solar and Stellar Astrophysics · Physics 2020-05-19 T. M. Sitnova , S. A. Yakovleva , A. K. Belyaev , L. I. Mashonkina

Rate coefficients for inelastic collisions between Li and H atoms covering all transitions between the asymptotic states Li(2s,2p,3s,3p,3d,4s,4p,4d,4f)+H(1s) and Li^+ +H^- are presented for the temperature range 2000-8000 K based on recent…

Astrophysics · Physics 2009-11-10 P. S. Barklem , A. K. Belyaev , M. Asplund

Iron plays a crucial role in studies of late-type stars. In their atmospheres, Fe I is the minority species and its lines are subject to the departures from LTE. In contrast, one believes that LTE is a realistic approximation for Fe II…

Solar and Stellar Astrophysics · Physics 2019-10-23 Lyudmila Mashonkina , Tatyana Sitnova , Svetlana A. Yakovleva , Andrey K. Belyaev

The non-LTE line formation for Al I and Si I was calculated with model atmospheres corresponding to F-G-K type stars of different metallicity. To account for inelastic collisions with H I, for the first time we applied the cross sections…

Solar and Stellar Astrophysics · Physics 2016-06-22 Lyudmila Mashonkina , Andrey K. Belyaev , Jianrong Shi

We present the non-local thermodynamic equilibrium (non-LTE) calculations for O I with the updated model atom that includes quantum-mechanical rate coefficients for O I + H I inelastic collisions from the recent study of Barklem (2018). The…

Solar and Stellar Astrophysics · Physics 2018-08-23 Tatyana Sitnova , Lyudmila Mashonkina

We perform the non-local thermodynamic equilibrium (NLTE) calculations for Ca I-II with the updated model atom that includes new quantum-mechanical rate coefficients for Ca I + H I collisions from two recent studies, that is, by Barklem and…

Solar and Stellar Astrophysics · Physics 2017-09-13 L. Mashonkina , T. Sitnova , A. K. Belyaev

Utilizing a simplified quantum model approach, the low-energy inelastic collision processes between yttrium atoms (ions) and hydrogen atoms have been studied. Rate coefficients corresponding to the mutual neutralization, ion-pair formation,…

Solar and Stellar Astrophysics · Physics 2023-08-16 Yu Wang , Sofya Alexeeva , Feng Wang , Ling Liu , Yong Wu , JianGuo Wang , Gang Zhao , Svetlana A. Yakovleva , Andrey K. Belyaev

Data for inelastic processes due to hydrogen atom collisions with iron are needed for accurate modelling of the iron spectrum in late-type stars. Excitation and charge transfer in low-energy Fe+H collisions is studied theoretically using a…

Solar and Stellar Astrophysics · Physics 2018-05-09 P. S. Barklem

Inelastic low-energy (0--1 eV) collisions of electrons with HeH$^+$ cations are treated theoretically, with a focus on the rovibrational excitation and dissociative recombination (DR) channels. In an application of {\it ab initio}…

Chemical Physics · Physics 2017-10-30 Roman Čurík , Chris H. Greene

We develop an analytic model of thermal state-to-state rotationally inelastic collisions of asymmetric-top molecules with closed-shell atoms in electric fields, and apply it to the Ar--H$_2$O collision system. The predicted cross sections…

Chemical Physics · Physics 2010-01-05 Mikhail Lemeshko , Bretislav Friedrich

We present an experimental study on the rotational inelastic scattering of OH ($X^2\Pi_{3/2}, J=3/2, f$) radicals with He and D$_2$ at collision energies between 100 and 500 cm$^{-1}$ in a crossed beam experiment. The OH radicals are state…

Modeling environments that are not in local thermal equilibrium, such as protoplanetary disks or planetary atmospheres, with molecular spectroscopic data from space telescopes requires knowledge of the rate coefficients of rovibrationally…

Atomic Physics · Physics 2023-10-10 Taha Selim , Ad van der Avoird , Gerrit C. Groenenboom

We investigate the role of hydrogen collisions in NLTE spectral line synthesis, and introduce a new general empirical recipe to determine inelastic charge transfer (CT) and bound-bound hydrogen collisional rates. This recipe is based on…

Solar and Stellar Astrophysics · Physics 2018-10-24 Rana Ezzeddine , Thibault Merle , Bertrand Plez , Marwan Gebran , Frédéric Thévenin , Mathieu Van der Swaelmen

State-selected total cross sections and thermal rate coefficients are computed for the HD + $ortho$-/$para$-H$_2$ rotational energy transfer collision at low temperatures: 2 K $\lesssim$ T $\lesssim$ 300 K. A modified H$_2$-H$_2$ potential…

Chemical Physics · Physics 2016-01-28 Renat A. Sultanov , Dennis Guster , S. K. Adhikari

Absolute cross sections for charge exchange, ionization, stripping and excitation in K^(+) - He collisions were measured in the ion energy range 0.7 - 10 keV. The experimental data and the schematic correlation diagrams are used to analyze…

The influence of the uncertainties in the rate coefficient data for electron-impact excitation and ionization on non-LTE Li line formation in cool stellar atmospheres is investigated. We examine the electron collision data used in previous…

Solar and Stellar Astrophysics · Physics 2015-05-27 Y. Osorio , P. S. Barklem , K. Lind , M. Asplund

The experimental characterization of scattering resonances in low energy collisions has proven to be a stringent test for quantum chemistry calculations. Previous measurements on the NO-H$_2$ system at energies down to $10$ cm$^{-1}$…

We provide cross sections and Maxwell rate coefficients for reactive collisions of slow electrons with BeH$^+$ ions on all the eighteen vibrational levels ($X{^{1}\Sigma^{+}},v_{i}^{+}=0,1,2,\dots,17$) using a Multichannel Quantum Defect…

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