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del Mazo-Sevillano P, Félix-González D, Aguado A, Sanz-Sanz C, Kwon DH, Roncero O. Vibrational, non-adiabatic and isotopic effects in the dynamics of the H 2 + H 2+ → H 3+ + H reaction: application to plasma modelling. Mol Phys 2023. [DOI: 10.1080/00268976.2023.2183071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Affiliation(s)
- P. del Mazo-Sevillano
- Department of Mathematics and Computer Science, FU Berlin, Berlin, Germany
- Unidad Asociada UAM-IFF-CSIC, Departamento de Química Física Aplicada, Facultad de Ciencias M-14, Universidad Autónoma de Madrid, Madrid, Spain
| | - D. Félix-González
- Unidad Asociada UAM-IFF-CSIC, Departamento de Química Física Aplicada, Facultad de Ciencias M-14, Universidad Autónoma de Madrid, Madrid, Spain
| | - A. Aguado
- Unidad Asociada UAM-IFF-CSIC, Departamento de Química Física Aplicada, Facultad de Ciencias M-14, Universidad Autónoma de Madrid, Madrid, Spain
| | - C. Sanz-Sanz
- Unidad Asociada UAM-IFF-CSIC, Departamento de Química Física Aplicada, Facultad de Ciencias M-14, Universidad Autónoma de Madrid, Madrid, Spain
| | - D.-H. Kwon
- Nuclear Physics Application Research Division, Korea Atomic Energy Research Institute, Daejeon, Republic of Korea
| | - O. Roncero
- Instituto de Física Fundamental, IFF-CSIC, Madrid, Spain
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Roncero O, Andrianarijaona V, Aguado A, Sanz-Sanz C. Vibrational effects in the quantum dynamics of the H + D 2+ charge transfer reaction. Mol Phys 2021. [DOI: 10.1080/00268976.2021.1948125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- O. Roncero
- IFF-CSIC, Instituto de Física Fundamental, Madrid, Spain
| | - V. Andrianarijaona
- Department of Physics, Pacific Union College, Angwin, CA, USA
- Department of Physics and Engineering, Southern Adventist University, Collegedale, TN, USA
| | - A. Aguado
- Unidad Asociada UAM-CSIC, Departamento de Química Física Aplicada, Universidad Autónoma de Madrid, Madrid, Spain
| | - C. Sanz-Sanz
- Unidad Asociada UAM-CSIC, Departamento de Química Física Aplicada, Universidad Autónoma de Madrid, Madrid, Spain
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Navarro-Almaida D, Le Gal R, Fuente A, Rivière-Marichalar P, Wakelam V, Cazaux S, Caselli P, Laas JC, Alonso-Albi T, Loison JC, Gerin M, Kramer C, Roueff E, Bachiller R, Commerçon B, Friesen R, García-Burillo S, Goicoechea JR, Giuliano BM, Jiménez-Serra I, Kirk JM, Lattanzi V, Malinen J, Marcelino N, Martín-Domènech R, Muñoz Caro GM, Pineda J, Tercero B, Treviño-Morales SP, Roncero O, Hacar A, Tafalla M, Ward-Thompson D. Gas phase Elemental abundances in Molecular cloudS (GEMS) II. On the quest for the sulphur reservoir in molecular clouds: the H 2S case. Astron Astrophys 2020; 637:A39. [PMID: 32565548 PMCID: PMC7305024 DOI: 10.1051/0004-6361/201937180] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
CONTEXT Sulphur is one of the most abundant elements in the Universe. Surprisingly, sulphuretted molecules are not as abundant as expected in the interstellar medium and the identity of the main sulphur reservoir is still an open question. AIMS Our goal is to investigate the H2S chemistry in dark clouds, as this stable molecule is a potential sulphur reservoir. METHODS Using millimeter observations of CS, SO, H2S, and their isotopologues, we determine the physical conditions and H2S abundances along the cores TMC 1-C, TMC 1-CP, and Barnard 1b. The gas-grain model Nautilus is used to model the sulphur chemistry and explore the impact of photo-desorption and chemical desorption on the H2S abundance. RESULTS Our modeling shows that chemical desorption is the main source of gas-phase H2S in dark cores. The measured H2S abundance can only be fitted if we assume that the chemical desorption rate decreases by more than a factor of 10 when n H > 2 × 104. This change in the desorption rate is consistent with the formation of thick H2O and CO ice mantles on grain surfaces. The observed SO and H2S abundances are in good agreement with our predictions adopting an undepleted value of the sulphur abundance. However, the CS abundance is overestimated by a factor of 5 - 10. Along the three cores, atomic S is predicted to be the main sulphur reservoir. CONCLUSIONS The gaseous H2S abundance is well reproduced, assuming undepleted sulphur abundance and chemical desorption as the main source of H2S. The behavior of the observed H2S abundance suggests a changing desorption efficiency, which would probe the snowline in these cold cores. Our model, however, highly overestimates the observed gas-phase CS abundance. Given the uncertainty in the sulphur chemistry, we can only conclude that our data are consistent with a cosmic elemental S abundance with an uncertainty of a factor of 10.
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Affiliation(s)
- D Navarro-Almaida
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - R Le Gal
- Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USA
| | - A Fuente
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | | | - V Wakelam
- Laboratoire d'Astrophysique de Bordeaux, Univ. Bordeaux, CNRS, B18N, allée Geoffroy Saint-Hilaire, 33615 Pessac, France
| | - S Cazaux
- Faculty of Aerospace Engineering, Delft University of Technology, Delft, The Netherlands; University of Leiden, P.O. Box 9513, NL, 2300 RA, Leiden, The Netherlands
| | - P Caselli
- Centre for Astrochemical Studies, Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748, Garching, Germany
| | - Jacob C Laas
- Centre for Astrochemical Studies, Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748, Garching, Germany
| | - T Alonso-Albi
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - J C Loison
- Institut des Sciences Moléculaires (ISM), CNRS, Univ. Bordeaux, 351 cours de la Libération, F-33400, Talence, France
| | - M Gerin
- Observatoire de Paris, PSL Research University, CNRS, École Normale Supérieure, Sorbonne Universités, UPMC Univ. Paris 06, 75005, Paris, France
| | - C Kramer
- Instituto Radioastronomía Milimétrica (IRAM), Av. Divina Pastora 7, Nucleo Central, 18012, Granada, Spain
| | - E Roueff
- Sorbonne Université, Observatoire de Paris, Université PSL, CNRS, LERMA, F-92190, Meudon, France
| | - R Bachiller
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - B Commerçon
- École Normale Supérieure de Lyon, CRAL, UMR CNRS 5574, Université Lyon I, 46 Allée d'Italie, 69364, Lyon Cedex 07, France
| | - R Friesen
- National Radio Astronomy Observatory, 520 Edgemont Rd., Charlottesville VA USA 22901
| | - S García-Burillo
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - J R Goicoechea
- Instituto de Física Fundamental (CSIC), Calle Serrano 123, 28006, Madrid, Spain
| | - B M Giuliano
- Centre for Astrochemical Studies, Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748, Garching, Germany
| | - I Jiménez-Serra
- Centro de Astrobiología (CSIC-INTA), Ctra. de Ajalvir, km 4, Torrejón de Ardoz, 28850, Madrid, Spain
| | - J M Kirk
- Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE, UK
| | - V Lattanzi
- Centre for Astrochemical Studies, Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748, Garching, Germany
| | - J Malinen
- Department of Physics, University of Helsinki, PO Box 64, 00014, Helsinki, Finland
- Institute of Physics I, University of Cologne, Cologne, Germany
| | - N Marcelino
- Instituto de Física Fundamental (CSIC), Calle Serrano 123, 28006, Madrid, Spain
| | - R Martín-Domènech
- Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USA
| | - G M Muñoz Caro
- Centro de Astrobiología (CSIC-INTA), Ctra. de Ajalvir, km 4, Torrejón de Ardoz, 28850, Madrid, Spain
| | - J Pineda
- Centre for Astrochemical Studies, Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748, Garching, Germany
| | - B Tercero
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - S P Treviño-Morales
- Chalmers University of Technology, Department of Space, Earth and Environment, SE-412 93 Gothenburg, Sweden
| | - O Roncero
- Instituto de Física Fundamental (CSIC), Calle Serrano 123, 28006, Madrid, Spain
| | - A Hacar
- Leiden Observatory, Leiden University, PO Box 9513, 2300-RA, Leiden, The Netherlands
| | - M Tafalla
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - D Ward-Thompson
- Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE, UK
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Fuente A, Navarro DG, Caselli P, Gerin M, Kramer C, Roueff E, Alonso-Albi T, Bachiller R, Cazaux S, Commercon B, Friesen R, García-Burillo S, Giuliano BM, Goicoechea JR, Gratier P, Hacar A, Jiménez-Serra I, Kirk J, Lattanzi V, Loison JC, Malinen J, Marcelino N, Martín-Doménech R, Muñoz-Caro G, Pineda J, Tafalla M, Tercero B, Ward-Thompson D, Treviño-Morales SP, Riviére-Marichalar P, Roncero O, Vidal T, Ballester MY. Gas phase Elemental abundances in Molecular cloudS (GEMS): I. The prototypical dark cloud TMC 1. Astron Astrophys 2019; 624:10.1051/0004-6361/201834654. [PMID: 31156252 PMCID: PMC6542666 DOI: 10.1051/0004-6361/201834654] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
GEMS is an IRAM 30m Large Program whose aim is determining the elemental depletions and the ionization fraction in a set of prototypical star-forming regions. This paper presents the first results from the prototypical dark cloud TMC 1. Extensive millimeter observations have been carried out with the IRAM 30m telescope (3 mm and 2 mm) and the 40m Yebes telescope (1.3 cm and 7 mm) to determine the fractional abundances of CO, HCO+, HCN, CS, SO, HCS+, and N2H+ in three cuts which intersect the dense filament at the well-known positions TMC 1-CP, TMC 1-NH3, and TMC 1-C, covering a visual extinction range from A V ~ 3 to ~20 mag. Two phases with differentiated chemistry can be distinguished: i) the translucent envelope with molecular hydrogen densities of 1-5×103 cm-3; and ii) the dense phase, located at A V > 10 mag, with molecular hydrogen densities >104 cm-3. Observations and modeling show that the gas phase abundances of C and O progressively decrease along the C+/C/CO transition zone (A V ~ 3 mag) where C/H ~ 8×10-5 and C/O~0.8-1, until the beginning of the dense phase at A V ~ 10 mag. This is consistent with the grain temperatures being below the CO evaporation temperature in this region. In the case of sulfur, a strong depletion should occur before the translucent phase where we estimate a S/H ~ (0.4 - 2.2) ×10-6, an abundance ~7-40 times lower than the solar value. A second strong depletion must be present during the formation of the thick icy mantles to achieve the values of S/H measured in the dense cold cores (S/H ~8×10-8). Based on our chemical modeling, we constrain the value of ζ H2 to ~ (0.5 - 1.8) ×10-16 s-1 in the translucent cloud.
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Affiliation(s)
- A Fuente
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - D G Navarro
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - P Caselli
- Centre for Astrochemical Studies, Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748, Garching, Germany
| | - M Gerin
- Observatoire de Paris, PSL Research University, CNRS, École Normale Supérieure, Sorbonne Universités, UPMC Univ. Paris 06, 75005, Paris, France
| | - C Kramer
- Instituto Radioastronomía Milimétrica (IRAM), Av. Divina Pastora 7, Nucleo Central, 18012, Granada, Spain
| | - E Roueff
- Sorbonne Université, Observatoire de Paris, Université PSL, CNRS, LERMA, F-92190, Meudon, France
| | - T Alonso-Albi
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - R Bachiller
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - S Cazaux
- Faculty of Aerospace Engineering, Delft University of Technology, Delft, The Netherlands ; University of Leiden, P.O. Box 9513, NL, 2300 RA, Leiden, The Netherlands
| | - B Commercon
- École Normale Supérieure de Lyon, CRAL, UMR CNRS 5574, Université Lyon I, 46 Allée d'Italie, 69364, Lyon Cedex 07, France
| | - R Friesen
- National Radio Astronomy Observatory, 520 Edgemont Rd., Charlottesville VA USA 22901
| | - S García-Burillo
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - B M Giuliano
- Centre for Astrochemical Studies, Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748, Garching, Germany
| | - J R Goicoechea
- Instituto de Física Fundamental (CSIC), Calle Serrano 123, 28006, Madrid, Spain
| | - P Gratier
- Laboratoire d'astrophysique de Bordeaux, Univ. Bordeaux, CNRS, B18N, allée Geoffroy Saint-Hilaire, 33615, Pessac, France
| | - A Hacar
- Leiden Observatory, Leiden University, PO Box 9513, 2300-RA, Leiden, The Netherlands
| | - I Jiménez-Serra
- Centro de Astrobiología (CSIC-INTA), Ctra. de Ajalvir, km 4, Torrejón de Ardoz, 28850, Madrid, Spain
| | - J Kirk
- Department of Physics, University of Warwick, Coventry CV4 7AL, UK
| | - V Lattanzi
- Centre for Astrochemical Studies, Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748, Garching, Germany
| | - J C Loison
- Institut des Sciences Moléculaires (ISM), CNRS, Univ. Bordeaux, 351 cours de la Libération, F-33400, Talence, France
| | - J Malinen
- Department of Physics, University of Helsinki, PO Box 64, 00014, Helsinki, Finland
- Institute of Physics I, University of Cologne, Cologne, Germany
| | - N Marcelino
- Instituto de Física Fundamental (CSIC), Calle Serrano 123, 28006, Madrid, Spain
| | - R Martín-Doménech
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA
| | - G Muñoz-Caro
- Centro de Astrobiología (CSIC-INTA), Ctra. de Ajalvir, km 4, Torrejón de Ardoz, 28850, Madrid, Spain
| | - J Pineda
- Centre for Astrochemical Studies, Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748, Garching, Germany
| | - M Tafalla
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - B Tercero
- Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain
| | - D Ward-Thompson
- Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE, UK
| | - S P Treviño-Morales
- Chalmers University of Technology, Department of Space, Earth and Environment, SE-412 93 Gothenburg, Sweden
| | | | - O Roncero
- Instituto de Física Fundamental (CSIC), Calle Serrano 123, 28006, Madrid, Spain
| | - T Vidal
- Laboratoire d'astrophysique de Bordeaux, Univ. Bordeaux, CNRS, B18N, allée Geoffroy Saint-Hilaire, 33615, Pessac, France
| | - Maikel Y Ballester
- Departamento de Física, Universidade Federal de Juiz de Fora-UFJF, Juiz de Fora, MG 36036-330, Brazil
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Ocaña AJ, Jiménez E, Ballesteros B, Canosa A, Antiñolo M, Albaladejo J, Agúndez M, Cernicharo J, Zanchet A, del Mazo P, Roncero O, Aguado A. Is the gas-phase OH+H 2CO reaction a source of HCO in interstellar cold dark clouds? A kinetic, dynamic and modelling study. Astrophys J 2017; 850:28. [PMID: 29880977 PMCID: PMC5988043 DOI: 10.3847/1538-4357/aa93d9] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Chemical kinetics of neutral-neutral gas-phase reactions at ultralow temperatures is a fascinating research subject with important implications on the chemistry of complex organic molecules in the interstellar medium (T∼10-100K). Scarce kinetic information is currently available for this kind of reactions at T<200 K. In this work we use the CRESU (Cinétique de Réaction en Ecoulement Supersonique Uniforme, which means Reaction Kinetics in a Uniform Supersonic Flow) technique to measure for the first time the rate coefficients (k) of the gas-phase OH+H2CO reaction between 22 and 107 K. k values greatly increase from 2.1×10-11 cm3 s-1 at 107 K to 1.2×10-10 cm3 s-1 at 22 K. This is also confirmed by quasi-classical trajectories (QCT) at collision energies down to 0.1 meV performed using a new full dimension and ab initio potential energy surface, recently developed which generates highly accurate potential and includes long range dipole-dipole interactions. QCT calculations indicate that at low temperatures HCO is the exclusive product for the OH+H2CO reaction. In order to revisit the chemistry of HCO in cold dense clouds, k is reasonably extrapolated from the experimental results at 10K (2.6×10-10 cm3 s-1). The modeled abundances of HCO are in agreement with the observations in cold dark clouds for an evolving time of 105-106 yrs. The different sources of production of HCO are presented and the uncertainties in the chemical networks discussed. This reaction can be expected to be a competitive process in the chemistry of prestellar cores. The present reaction is shown to account for a few percent of the total HCO production rate. Extensions to photodissociation regions and diffuse clouds environments are also commented.
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Affiliation(s)
- A. J. Ocaña
- Departamento de Química Física. Facultad de Ciencias y Tecnologías Químicas. Universidad de Castilla-La Mancha. Avda. Camilo José Cela 1B. 13071, Ciudad Real, Spain
| | - E. Jiménez
- Departamento de Química Física. Facultad de Ciencias y Tecnologías Químicas. Universidad de Castilla-La Mancha. Avda. Camilo José Cela 1B. 13071, Ciudad Real, Spain
- Instituto de Investigación en Combustión y Contaminación Atmosférica. Universidad de Castilla-La Mancha. Camino de Moledores s/n. 13071, Ciudad Real, Spain
| | - B. Ballesteros
- Departamento de Química Física. Facultad de Ciencias y Tecnologías Químicas. Universidad de Castilla-La Mancha. Avda. Camilo José Cela 1B. 13071, Ciudad Real, Spain
- Instituto de Investigación en Combustión y Contaminación Atmosférica. Universidad de Castilla-La Mancha. Camino de Moledores s/n. 13071, Ciudad Real, Spain
| | - A. Canosa
- Institut de Physique de Rennes, UMR 6251 CNRS-Université de Rennes 1. Campus de Beaulieu, Bât 11C, 263 Av. Général Leclerc, 35042, Rennes, France
| | - M. Antiñolo
- Instituto de Investigación en Combustión y Contaminación Atmosférica. Universidad de Castilla-La Mancha. Camino de Moledores s/n. 13071, Ciudad Real, Spain
| | - J. Albaladejo
- Departamento de Química Física. Facultad de Ciencias y Tecnologías Químicas. Universidad de Castilla-La Mancha. Avda. Camilo José Cela 1B. 13071, Ciudad Real, Spain
- Instituto de Investigación en Combustión y Contaminación Atmosférica. Universidad de Castilla-La Mancha. Camino de Moledores s/n. 13071, Ciudad Real, Spain
| | - M. Agúndez
- Instituto de Ciencia de Materiales de Madrid. Consejo Superior de Investigaciones Científicas. C/ Sor Juana Inés de la Cruz, 3. 28049, Cantoblanco, Madrid, Spain
| | - J. Cernicharo
- Instituto de Ciencia de Materiales de Madrid. Consejo Superior de Investigaciones Científicas. C/ Sor Juana Inés de la Cruz, 3. 28049, Cantoblanco, Madrid, Spain
| | - A. Zanchet
- Instituto de Física Fundamental, CSIC, C/ Serrano, 123, 28006 Madrid, Spain
| | - P. del Mazo
- Instituto de Física Fundamental, CSIC, C/ Serrano, 123, 28006 Madrid, Spain
| | - O. Roncero
- Instituto de Física Fundamental, CSIC, C/ Serrano, 123, 28006 Madrid, Spain
| | - A. Aguado
- Departamento de Química Física Aplicada (UAM), Unidad Asociada IFF-CSIC, Facultad de Ciencias C-XIV, Universidad Autónoma de Madrid, 28049, Madrid, Spain
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Faure A, Halvick P, Stoecklin T, Honvault P, Epée Epée MD, Mezei JZ, Motapon O, Schneider IF, Tennyson J, Roncero O, Bulut N, Zanchet A. State-to-state chemistry and rotational excitation of CH + in photon-dominated regions. Mon Not R Astron Soc 2017; 469:612-620. [PMID: 28690343 PMCID: PMC5500105 DOI: 10.1093/mnras/stx892] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We present a detailed theoretical study of the rotational excitation of CH+ due to reactive and nonreactive collisions involving C+(2P), H2, CH+, H and free electrons. Specifically, the formation of CH+ proceeds through the reaction between C+(2P) and H2(νH2 = 1, 2), while the collisional (de)excitation and destruction of CH+ is due to collisions with hydrogen atoms and free electrons. State-to-state and initial-state-specific rate coefficients are computed in the kinetic temperature range 10-3000 K for the inelastic, exchange, abstraction and dissociative recombination processes using accurate potential energy surfaces and the best scattering methods. Good agreement, within a factor of 2, is found between the experimental and theoretical thermal rate coefficients, except for the reaction of CH+ with H atoms at kinetic temperatures below 50 K. The full set of collisional and chemical data are then implemented in a radiative transfer model. Our Non-LTE calculations confirm that the formation pumping due to vibrationally excited H2 has a substantial effect on the excitation of CH+ in photon-dominated regions. In addition, we are able to reproduce, within error bars, the far-infrared observations of CH+ toward the Orion Bar and the planetary nebula NGC 7027. Our results further suggest that the population of νH2 = 2 might be significant in the photon-dominated region of NGC 7027.
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Affiliation(s)
- A. Faure
- Univ. Grenoble Alpes, CNRS, IPAG, F-38000 Grenoble, France
| | - P. Halvick
- Univ. Bordeaux, CNRS, ISM, F-33400 Talence, France
| | - T. Stoecklin
- Univ. Bordeaux, CNRS, ISM, F-33400 Talence, France
| | - P. Honvault
- Univ. Bourgogne Franche-Comté, Laboratoire ICB, F-21078 Dijon, France
| | - M. D. Epée Epée
- UFD Mathématiques, Informatique Appliqúee et Physique Fondamentale, University of Douala, P. O. Box 24157, Douala, Cameroon
| | - J. Zs. Mezei
- Univ. Normandie, CNRS, LOMC, F-76058 Le Havre, France
- LSPM, Univ. Paris 13, 99 avenue Jean-Baptiste Clément, F-93430 Villetaneuse, France
- Univ. Paris-Sud, CNRS, Laboratoire Aimé Cotton, F-91405 Orsay, France
- Institute of Nuclear Research of the Hungarian Academy of Sciences, P.O. Box 51, Debrecen H-4001, Hungary
| | - O. Motapon
- UFD Mathématiques, Informatique Appliqúee et Physique Fondamentale, University of Douala, P. O. Box 24157, Douala, Cameroon
- University of Maroua, Faculty of Science, P. O. Box 814 Maroua, Cameroon
| | - I. F. Schneider
- Univ. Normandie, CNRS, LOMC, F-76058 Le Havre, France
- Univ. Paris-Sud, CNRS, Laboratoire Aimé Cotton, F-91405 Orsay, France
| | - J. Tennyson
- Department of Physics and Astronomy, University College, London, Gower St., London WC1E 6BT, UK
| | - O. Roncero
- Instituto de Física Fundamental, CSIC, C/ Serrano, 123, E-28006 Madrid, Spain
| | - N. Bulut
- Firat University, Department of Physics, 23169 Elazig̃, Turkey
| | - A. Zanchet
- Instituto de Física Fundamental, CSIC, C/ Serrano, 123, E-28006 Madrid, Spain
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Abstract
As many organic molecules, formic acid (HCOOH) has two conformers (trans and cis). The energy barrier to internal conversion from trans to cis is much higher than the thermal energy available in molecular clouds. Thus, only the most stable conformer (trans) is expected to exist in detectable amounts. We report the first interstellar detection of cis-HCOOH. Its presence in ultraviolet (UV) irradiated gas exclusively (the Orion Bar photodissociation region), with a low trans-to-cis abundance ratio of 2.8 ± 1.0, supports a photoswitching mechanism: a given conformer absorbs a stellar photon that radiatively excites the molecule to electronic states above the interconversion barrier. Subsequent fluorescent decay leaves the molecule in a different conformer form. This mechanism, which we specifically study with ab initio quantum calculations, was not considered in Space before but likely induces structural changes of a variety of interstellar molecules submitted to UV radiation.
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Affiliation(s)
- S Cuadrado
- Grupo de Astrofísica Molecular. Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Sor Juana Ines de la Cruz 3, E-28049 Cantoblanco, Madrid, Spain
| | - J R Goicoechea
- Grupo de Astrofísica Molecular. Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Sor Juana Ines de la Cruz 3, E-28049 Cantoblanco, Madrid, Spain
| | - O Roncero
- Instituto de Física Fundamental (IFF-CSIC). Calle Serrano 123, E-28006 Madrid, Spain
| | - A Aguado
- Facultad de Ciencias, Unidad Asociada de Química-Física Aplicada CSIC-UAM, Universidad Autónoma de Madrid, E-28049, Madrid, Spain
| | - B Tercero
- Grupo de Astrofísica Molecular. Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Sor Juana Ines de la Cruz 3, E-28049 Cantoblanco, Madrid, Spain
| | - J Cernicharo
- Grupo de Astrofísica Molecular. Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Sor Juana Ines de la Cruz 3, E-28049 Cantoblanco, Madrid, Spain
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Fuente A, Cernicharo J, Roueff E, Gerin M, Pety J, Marcelino N, Bachiller R, Lefloch B, Roncero O, Aguado A. Ionization fraction and the enhanced sulfur chemistry in Barnard 1. Astron Astrophys 2016; 593:A94. [PMID: 27708436 PMCID: PMC5047358 DOI: 10.1051/0004-6361/201628285] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
CONTEXT Barnard B1b has revealed as one of the most interesting globules from the chemical and dynamical point of view. It presents a rich molecular chemistry characterized by large abundances of deuterated and complex molecules. Furthermore, it hosts an extremely young Class 0 object and one candidate to First Hydrostatic Core (FHSC) proving the youth of this star forming region. AIMS Our aim is to determine the cosmic ray ionization rate, [Formula: see text], and the depletion factors in this extremely young star forming region. These parameteres determine the dynamical evolution of the core. METHODS We carried out a spectral survey towards Barnard 1b as part of the IRAM Large program ASAI using the IRAM 30-m telescope at Pico Veleta (Spain). This provided a very complete inventory of neutral and ionic C-, N- and S- bearing species with, up to our knowledge, the first secure detections of the deuterated ions DCS+ and DOCO+. We use a state-of-the-art pseudo-time-dependent gas-phase chemical model that includes the ortho and para forms of [Formula: see text] and [Formula: see text] to determine the local value of the cosmic ray ionization rate and the depletion factors. RESULTS Our model assumes n(H2)=105 cm-3 and T k =12 K, as derived from our previous works. The observational data are well fitted with ζH2 between 3×10-17 s-1 and 10-16 s-1, and the following elemental abundances: O/H=3 10-5, N/H=6.4-8 10-5, C/H=1.7 10-5 and S/H between 6.0 10-7 and 1.0 10-6. The large number of neutral/protonated species detected, allows us to derive the elemental abundances and cosmic ray ionization rate simultaneously. Elemental depletions are estimated to be ~10 for C and O, ~1 for N and ~25 for S. CONCLUSIONS Barnard B1b presents similar depletions of C and O than those measured in pre-stellar cores. The depletion of sulfur is higher than that of C and O but not as extreme as in cold cores. In fact, it is similar to the values found in some bipolar outflows, hot cores and photon-dominated regions. Several scenarios are discussed to account for these peculiar abundances. We propose that it is the consequence of the initial conditions (important outflows and enhanced UV fields in the surroundings) and a rapid collapse (~0.1 Myr) that permits to maintain most S- and N-bearing species in gas phase to great optical depths. The interaction of the compact outflow associated with B1b-S with the surrounding material could enhance the abundances of S-bearing molecules, as well.
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Affiliation(s)
- A Fuente
- Observatorio Astronómico Nacional (OAN,IGN), Apdo 112, E-28803 Alcalá de Henares (Spain)
| | - J Cernicharo
- Instituto de Ciencia de Materiales de Madrid, ICMM-CSIC, C/ Sor Juana Inés de la Cruz 3, E-28049 Cantoblanco, Spain
| | - E Roueff
- CNRS UMR 8112, LERMA, Observatoire de Paris and École Normale Supérieure. 24 rue Lhomond, 75231 Paris Cedex 05, France; Sorbonne Universités, UPMC Univ. Paris 06, UMR8112, LERMA, F-75005 Paris, France
| | - M Gerin
- CNRS UMR 8112, LERMA, Observatoire de Paris and École Normale Supérieure. 24 rue Lhomond, 75231 Paris Cedex 05, France; Sorbonne Universités, UPMC Univ. Paris 06, UMR8112, LERMA, F-75005 Paris, France
| | - J Pety
- Institut de Radioastronomie Millimétrique, 300 Rue de la Piscine, F-38406 Saint Martin d'Héres, France
| | - N Marcelino
- INAF, Osservatorio di Radioastronomia, via P. Gobetti 101, I-40129, Bologna, Italy
| | - R Bachiller
- Observatorio Astronómico Nacional (OAN,IGN), Apdo 112, E-28803 Alcalá de Henares (Spain)
| | - B Lefloch
- Institut de Planétologie et d'Astrophysique de Grenoble (IPAG) UMR 5274, Universit UJF-Grenoble 1/CNRS-INSU, F-38041 Grenoble, France
| | - O Roncero
- Instituto de Física Fundamental (IFF-CSIC), C.S.I.C., Serrano 123, E-28006 Madrid, Spain
| | - A Aguado
- Facultad de Ciencias, Unidad Asociada de Química-Física Aplicada CSIC-UAM, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
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Bulut N, Castillo J, Jambrina PG, Kłos J, Roncero O, Aoiz FJ, Bañares L. Accurate Time-Dependent Wave Packet Calculations for the O+ + H2 → OH+ + H Ion–Molecule Reaction. J Phys Chem A 2015; 119:11951-62. [DOI: 10.1021/acs.jpca.5b00815] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- N. Bulut
- Department of Physics, Firat University, 23169 Elazig̃, Turkey
| | - J.F. Castillo
- Departamento
de Química Física I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid (Unidad Asociada I+D+i CSIC), 28040 Madrid, Spain
| | - P. G. Jambrina
- Departamento
de Química Física I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid (Unidad Asociada I+D+i CSIC), 28040 Madrid, Spain
| | - J. Kłos
- Department of Chemistry
and Biochemistry, University of Maryland, College Park, Maryland 20742-2021, United States
| | - O. Roncero
- Departamento de Física Atómica, Molecular y de Agregados,
Instituto de Física Fundamental, CSIC, C/Serrano, 123, 28006 Madrid, Spain
| | - F. J. Aoiz
- Departamento
de Química Física I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid (Unidad Asociada I+D+i CSIC), 28040 Madrid, Spain
| | - L. Bañares
- Departamento
de Química Física I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid (Unidad Asociada I+D+i CSIC), 28040 Madrid, Spain
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Krasil’nikov MB, Vasyutinskii OS, Roncero O. Angular momentum polarization of the molecules in the Li + HF reaction. Russ J Phys Chem B 2013. [DOI: 10.1134/s199079311301003x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Gómez-Carrasco S, Bulut N, Bañares L, Roncero O. Wave packet calculations on nonadiabatic effects for the O(3P)+HF(1Σ+) reaction under hyperthermal conditions. J Chem Phys 2012; 137:114309. [PMID: 22998264 DOI: 10.1063/1.4753811] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We present wave packet calculations of total and state-to-state reaction probabilities and integral cross sections for the nonadiabatic dynamics of the O((3)P)+HF → F((2)P)+OH((2)Π) reaction at hyperthermal collision energies ranging from 1.2 to 2.4 eV. The validity of the centrifugal sudden approximation is discussed for the title reaction and a comprehensive investigation of the influence of nonadiabatic effects on the dynamics of this reactive system at high (hyperthermal) collision energies is presented. In general, nonadiabatic effects are negligible for averaged observables, such as total reaction probabilities and integral cross sections, but they are clearly observed in detailed observables such as rotationally state-resolved reaction probabilities. A critical discussion of nonadiabatic effects on the dynamics of the title reaction is carried out by comparing with the reverse reaction and the characteristics of the adiabatic and diabatic potential energy surfaces involved.
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Affiliation(s)
- S Gómez-Carrasco
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad de Salamanca, Plaza de los Caídos s/n, 37008 Salamanca, Spain
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Zanchet A, González-Lezana T, Roncero O, Jorfi M, Honvault P, Hankel M. An accurate study of the dynamics of the C+OH reaction on the second excited 14A″ potential energy surface. J Chem Phys 2012; 136:164309. [DOI: 10.1063/1.4705426] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Sanz-Sanz C, Sanz AS, González-Lezana T, Roncero O, Miret-Artés S. Communication: Quantum Zeno-based control mechanism for molecular fragmentation. J Chem Phys 2012; 136:121101. [PMID: 22462825 DOI: 10.1063/1.3698278] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
A quantum control mechanism is proposed for molecular fragmentation processes within a scenario grounded on the quantum Zeno effect. In particular, we focus on the van der Waals Ne-Br(2) complex, which displays two competing dissociation channels via vibrational and electronic predissociation. Accordingly, realistic three-dimensional wave packet simulations are carried out by using ab initio interaction potentials recently obtained to reproduce available experimental data. Two numerical models to simulate the repeated measurements are reported and analyzed. It is found that the otherwise fast vibrational predissociation is slowed down in favor of the slow electronic (double fragmentation) predissociation, which is enhanced by several orders of magnitude. Based on these theoretical predictions, some hints to experimentalists to confirm their validity are also proposed.
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Affiliation(s)
- C Sanz-Sanz
- Instituto de Física Fundamental-CSIC, Serrano 123, 28006 Madrid, Spain
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Aslan E, Bulut N, Castillo JF, Bañares L, Roncero O, Aoiz FJ. Accurate Time-Dependent Wave Packet Study of the Li + H2+ Reaction and Its Isotopic Variants. J Phys Chem A 2011; 116:132-8. [DOI: 10.1021/jp210254t] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- E. Aslan
- Department of Physics, Firat University, 23169 Elazig̃, Turkey
| | - N. Bulut
- Department of Physics, Firat University, 23169 Elazig̃, Turkey
| | - J. F. Castillo
- Departamento de Química Física I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - L. Bañares
- Departamento de Química Física I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - O. Roncero
- Instituto de Física Fundamental, CSIC, C/Serrano, 123, 28006 Madrid, Spain
| | - F. J. Aoiz
- Departamento de Química Física I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
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González-Sánchez L, Vasyutinskii O, Zanchet A, Sanz-Sanz C, Roncero O. Quantum stereodynamics of Li + HF reactive collisions: the role of reactants polarization on the differential cross section. Phys Chem Chem Phys 2011; 13:13656-69. [DOI: 10.1039/c0cp02452j] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Aguado A, Barragán P, Prosmiti R, Delgado-Barrio G, Villarreal P, Roncero O. A new accurate and full dimensional potential energy surface of H5+ based on a triatomics-in-molecules analytic functional form. J Chem Phys 2010; 133:024306. [DOI: 10.1063/1.3454658] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Pérez de Tudela R, Márquez-Mijares M, González-Lezana T, Roncero O, Miret-Artés S, Delgado-Barrio G, Villarreal P. A path-integral Monte Carlo study of a small cluster: The Ar trimer. J Chem Phys 2010; 132:244303. [DOI: 10.1063/1.3445773] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Zanchet A, Roncero O, González-Lezana T, Rodríguez-López A, Aguado A, Sanz-Sanz C, Gómez-Carrasco S. Differential Cross Sections and Product Rotational Polarization in A + BC Reactions Using Wave Packet Methods: H+ + D2 and Li + HF Examples. J Phys Chem A 2009; 113:14488-501. [DOI: 10.1021/jp9038946] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- A. Zanchet
- Instituto de Física Fundamental, CSIC, Unidad Asociada UAM-CSIC, Serrano 123, 28006 Madrid, Spain, Centro de Supercomputación de Galicia, Av. de Vigo s/n (Campus Sur), 15706 Santiago de Compostela, Spain, and Departamento de Química Física, Facultad de Ciencias C-XIV, Unidad Asociada UAM-CSIC, Universidad Autónoma de Madrid, 28049, Madrid, Spain, School of Chemistry, University of Birmingham, Edbaston, Birmingham B15 2TT, United Kingdom, and Theoretical Chemistry Department, Institute of Physical
| | - O. Roncero
- Instituto de Física Fundamental, CSIC, Unidad Asociada UAM-CSIC, Serrano 123, 28006 Madrid, Spain, Centro de Supercomputación de Galicia, Av. de Vigo s/n (Campus Sur), 15706 Santiago de Compostela, Spain, and Departamento de Química Física, Facultad de Ciencias C-XIV, Unidad Asociada UAM-CSIC, Universidad Autónoma de Madrid, 28049, Madrid, Spain, School of Chemistry, University of Birmingham, Edbaston, Birmingham B15 2TT, United Kingdom, and Theoretical Chemistry Department, Institute of Physical
| | - T. González-Lezana
- Instituto de Física Fundamental, CSIC, Unidad Asociada UAM-CSIC, Serrano 123, 28006 Madrid, Spain, Centro de Supercomputación de Galicia, Av. de Vigo s/n (Campus Sur), 15706 Santiago de Compostela, Spain, and Departamento de Química Física, Facultad de Ciencias C-XIV, Unidad Asociada UAM-CSIC, Universidad Autónoma de Madrid, 28049, Madrid, Spain, School of Chemistry, University of Birmingham, Edbaston, Birmingham B15 2TT, United Kingdom, and Theoretical Chemistry Department, Institute of Physical
| | - A. Rodríguez-López
- Instituto de Física Fundamental, CSIC, Unidad Asociada UAM-CSIC, Serrano 123, 28006 Madrid, Spain, Centro de Supercomputación de Galicia, Av. de Vigo s/n (Campus Sur), 15706 Santiago de Compostela, Spain, and Departamento de Química Física, Facultad de Ciencias C-XIV, Unidad Asociada UAM-CSIC, Universidad Autónoma de Madrid, 28049, Madrid, Spain, School of Chemistry, University of Birmingham, Edbaston, Birmingham B15 2TT, United Kingdom, and Theoretical Chemistry Department, Institute of Physical
| | - A. Aguado
- Instituto de Física Fundamental, CSIC, Unidad Asociada UAM-CSIC, Serrano 123, 28006 Madrid, Spain, Centro de Supercomputación de Galicia, Av. de Vigo s/n (Campus Sur), 15706 Santiago de Compostela, Spain, and Departamento de Química Física, Facultad de Ciencias C-XIV, Unidad Asociada UAM-CSIC, Universidad Autónoma de Madrid, 28049, Madrid, Spain, School of Chemistry, University of Birmingham, Edbaston, Birmingham B15 2TT, United Kingdom, and Theoretical Chemistry Department, Institute of Physical
| | - C. Sanz-Sanz
- Instituto de Física Fundamental, CSIC, Unidad Asociada UAM-CSIC, Serrano 123, 28006 Madrid, Spain, Centro de Supercomputación de Galicia, Av. de Vigo s/n (Campus Sur), 15706 Santiago de Compostela, Spain, and Departamento de Química Física, Facultad de Ciencias C-XIV, Unidad Asociada UAM-CSIC, Universidad Autónoma de Madrid, 28049, Madrid, Spain, School of Chemistry, University of Birmingham, Edbaston, Birmingham B15 2TT, United Kingdom, and Theoretical Chemistry Department, Institute of Physical
| | - S. Gómez-Carrasco
- Instituto de Física Fundamental, CSIC, Unidad Asociada UAM-CSIC, Serrano 123, 28006 Madrid, Spain, Centro de Supercomputación de Galicia, Av. de Vigo s/n (Campus Sur), 15706 Santiago de Compostela, Spain, and Departamento de Química Física, Facultad de Ciencias C-XIV, Unidad Asociada UAM-CSIC, Universidad Autónoma de Madrid, 28049, Madrid, Spain, School of Chemistry, University of Birmingham, Edbaston, Birmingham B15 2TT, United Kingdom, and Theoretical Chemistry Department, Institute of Physical
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Márquez-Mijares M, Pérez de Tudela R, González-Lezana T, Roncero O, Miret-Artés S, Delgado-Barrio G, Villarreal P, Baccarelli I, Gianturco FA, Rubayo-Soneira J. A theoretical investigation on the spectrum of the Ar trimer for high rotational excitations. J Chem Phys 2009; 130:154301. [DOI: 10.1063/1.3115100] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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21
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Zanchet A, Dorta-Urra A, Roncero O, Flores F, Tablero C, Paniagua M, Aguado A. Mechanism of molecular hydrogen dissociation on gold chains and clusters as model prototypes of nanostructures. Phys Chem Chem Phys 2009; 11:10122-31. [DOI: 10.1039/b910200k] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Roncero O, de Lara-Castells MP, Villarreal P, Flores F, Ortega J, Paniagua M, Aguado A. An inversion technique for the calculation of embedding potentials. J Chem Phys 2008; 129:184104. [DOI: 10.1063/1.3007987] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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23
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Roncero O, de Lara-Castells MP, Delgado-Barrio G, Villarreal P, Stoecklin T, Voronin A, Rayez JC. Exact, Born-Oppenheimer, and quantum-chemistry-like calculations in helium clusters doped with light molecules: The He2N2(X) system. J Chem Phys 2008; 128:164313. [PMID: 18447445 DOI: 10.1063/1.2900560] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Helium clusters doped with diatomic molecules, He(N)-BC, have been recently studied by means of a quantum-chemistry-like approach. The model treats He atoms as "electrons" and dopants as "nuclei" in standard electronic structure calculations. Due to the large mass difference between He atoms and electrons, and to the replacement of Coulomb interactions by intermolecular potentials, it is worth assessing up to what extent are the approximations involved in this model, i.e., decoupling of the BC rotation from the He-atom orbital angular momenta and Born-Oppenheimer separation of the BC stretch versus the He motions, accurate enough. These issues have been previously tackled elsewhere for the (4)He(2)-Br(2)(X) system, which contains a heavy dopant [Roncero et al., Int. J. Quantum Chem. 107, 2756 (2007)]. Here, we consider a similar cluster but with a much lighter dopant such as N(2)(X). Although the model does not provide the correct energy levels for the cluster, positions and intensities of the main detectable lines of the vibrotational Raman spectrum at low temperature are accurately reproduced.
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Affiliation(s)
- O Roncero
- Instituto de Física Fundamental (C.S.I.C.), Serrano 123, E-28006 Madrid, Spain
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Gloaguen E, Sanz Sanz C, Collier M, Gaveau MA, Soep B, Roncero O, Mestdagh JM. Transition-state spectroscopy of the photoinduced Ca + CH3F reaction. 3. Reaction following the local excitation to Ca(4s3d 1D). J Phys Chem A 2008; 112:1408-20. [PMID: 18232672 DOI: 10.1021/jp077664g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The Ca* + CH3F --> CaF* + CH3 reaction was studied both experimentally and theoretically. The reaction was photoinduced in Ca...CH3F complexes, which were illuminated by a tunable laser in the range 18 000-24 000 cm-1. The absorption band that leads to the reaction extends between 19 000 and 23 000 cm-1. It is formed of three broad overlapping structures corresponding to the excitation of different electronic states of the complex. The two structures of lowest energy were considered in detail. They are associated with two series of respectively 2 and 3 molecular states correlating to Ca(4s3d 1D) + CH3F at infinite separation between Ca and CH3F. The assignment of these structures to specific electronic transitions of the complex stemmed from theoretical calculations where the Ca...CH3F complex is described by a linear Ca-F-C backbone. 2D potential energy surfaces were calculated by associating a pseudopotential description of the [Ca2+] and [F7+] cores, a core polarization operator on calcium, an extensive Gaussian basis, and a treatment of the electronic problem at the CI-MRCI level. All the excited levels correlating to the 4s2 1S, 4s3d 1D, and 4s4p 1P levels of Ca in the Ca + CH3F channel were documented in a calculation that explored the rearrangement channels where either Ca + CH3F or CaF + CH3 are formed. Then, wavepacket calculations on the 2D-PES's allowed one to simulate the absorption spectrum of the complex, in an approximation where the various electronic states of the complex are not coupled together. The assignment above stemmed from this. The second outcome of the calculation was that whatever the excited level of the complex that is considered, the reaction has to proceed through energy barriers. The electronic excitation of the complex on the red side of the absorption band does not seem to deposit enough energy in the system to overcome these barriers (even the lowest one) or to stimulate tunneling reactions. An alternative reaction mechanism involving a transfer to triplet PES's is proposed.
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Affiliation(s)
- E Gloaguen
- Laboratoire Francis Perrin (CNRS-URA-2453), DSM/IRAMIS/Service des Photons, Atomes et Molécules, C.E.A. Saclay, F-91191 Gif-sur-Yvette cedex, France
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González-Lezana T, Aguado A, Paniagua M, Roncero O. Quantum approaches for the insertion dynamics of the H+ + D2 and D+ + H2 reactive collisions. J Chem Phys 2007; 123:194309. [PMID: 16321090 DOI: 10.1063/1.2118567] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The H(+)+D(2) and D(+)+H(2) reactive collisions are studied using a recently proposed adiabatic potential energy surface of spectroscopic accuracy. The dynamics is studied using an exact wave packet method on the adiabatic surface at energies below the curve crossing occurring at approximately 1.5 eV above the threshold. It is found that the reaction is very well described by a statistical quantum method for a zero total angular momentum (J) as compared with the exact ones, while for higher J some discrepancies are found. For J >0 different centrifugal sudden approximations are proposed and compared with the exact and statistical quantum treatments. The usual centrifugal sudden approach fails by considering too high reaction barriers and too low reaction probabilities. A new statistically modified centrifugal sudden approach is considered which corrects these two failures to a rather good extent. It is also found that an adiabatic approximation for the helicities provides results in very good agreement with the statistical method, placing the reaction barrier properly. However, both statistical and adiabatic centrifugal treatments overestimate the reaction probabilities. The reaction cross sections thus obtained with the new approaches are in rather good agreement with the exact results. In spite of these deficiencies, the quantum statistical method is well adapted for describing the insertion dynamics, and it is then used to evaluate the differential cross sections.
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Affiliation(s)
- Tomas González-Lezana
- Unidad Asociada Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas (UAM-CSIC), Instituto de Matemáticas y Física Fundamental, Consejo Superior de Investigaciones Científicas (CSIC), Serrano 123, Madrid 28006, Spain
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Affiliation(s)
- F.A. Gianturco
- a Department of Chemistry , University of Rome, Citta Universitaria , 00185 , Rome , Italy
| | - M. Patriarca
- a Department of Chemistry , University of Rome, Citta Universitaria , 00185 , Rome , Italy
| | - O. Roncero
- a Department of Chemistry , University of Rome, Citta Universitaria , 00185 , Rome , Italy
- b Instituto de Estructura de la Materia, CSIC , Serrano 123, 28006 , Madrid , Spain
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Sanz C, van der Avoird A, Roncero O. Collisional and photoinitiated reaction dynamics in the ground electronic state of Ca-HCl. J Chem Phys 2005; 123:64301. [PMID: 16122302 DOI: 10.1063/1.1995700] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Ca+HCl(upsilon,j) reactive collisions were studied for different rovibrational states of the HCl reactant using wave-packet calculations in reactant Jacobi coordinates. A recently proposed potential-energy surface was used with a barrier of approximately 0.4 eV followed by a deep well. The possibility of an insertion mechanism due to this last well has been analyzed and it was found that once the wave packet passes over the barrier most of it goes directly to CaCl+H products, which shows that the reaction dynamics is essentially direct. It was also found that there is no significant change in the reaction efficiency as a function of the initial HCl rovibrational state, because CaHCl at the barrier has an only little elongated HCl bond. Near the threshold for reaction with HCl(upsilon=0), however, the reaction shows significant steric effects for j > 0. In a complementary study, the infrared excitation from the Ca-HCl van der Waals well was simulated. The spectrum thus obtained shows several series of resonances which correspond to quasibound states correlating to excited HCl(upsilon) vibrations. The Ca-HCl binding energies of these quasibound states increase dramatically with upsilon, from 75 to 650 cm(-1), because the wave function spreads increasingly over larger HCl bond lengths. Thus it explores the region of the barrier saddle point and the deep insertion well. Although also the charge-transfer contribution increases with upsilon, the reaction probability for resonances of the upsilon=2 manifold, which are well above the reaction threshold, is still negligible. This explains the relatively long lifetimes of these upsilon=2 resonances. The reaction probability becomes significant at upsilon=3. Our simulations have shown that an experimental study of this type will allow a gradual spectroscopic probing of the barrier for the reaction.
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Affiliation(s)
- Cristina Sanz
- Instituto de Matemáticas y Física Fundamental, Consejo Superior de Investigaciones Científicas (CSIC), Serrano 123, 28006 Madrid, Spain
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Taxonera C, Roncero O, Fernández S, Rey Díaz-Rubio E, Sevilla C, Pérez de la Serna J, Díaz-Rubio M. Impact of the recommendations made by Spanish Club for the Study of Helicobacter pylori on eradication indications. Rev Esp Enferm Dig 2002; 94:332-9. [PMID: 12432590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Abstract
AIM A Spanish Consensus Conference had been arranged by the Spanish Club for the Study of Helicobacter pylori to encourage the use of eradication regimens in appropriate indications. The aim of our study was to assess whether the publication of these recommendations in November 1999 induced a change on the indications of eradication in the referring primary care district. METHOD Patients who had undergone Helicobacter pylori eradication therapy indicated by a gastroenterologist and referred to perform the 13C-labelled marked urea breath test were evaluated. Indications of eradication therapy were analysed and divided in: a) use of Conference recommended procedures (duodenal or gastric ulcer, erosive duodenitis, gastric MALT lymphoma and after resection of gastric adenocarcinoma); and b) other procedures not included in the recommendations (the rest). Indications established during former and latter years of publication of the Club's recommendations were compared. RESULTS A total of 659 established eradications in 1999 against 537 in 2000, were studied. Regarding established eradications in 1999, 418 out of 659 (63%) followed the recommendations made by the Spanish Club, while 241 (37%) did not. In 2000, the proportion of eradication therapy administered using the recommendations made by the Spanish Club was similar to previous year: 338 (63%) followed the recommendations, against 199 (37%) that did not (p = not significant). In both years, considering those indications not recommended, patients either with superficial chronic gastritis with or without dyspepsia or with gastrooesophageal reflux disease were the main disorders to indicate eradication therapy. CONCLUSIONS The recommendations of the Spanish Helicobacter pylori Study Club have not triggered a significant change after their publication on the indications for Helicobacter pylori eradication therapy in the setting studied.
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Affiliation(s)
- C Taxonera
- Servicio Aparato Digestivo, Hospital Clínico San Carlos, Prof. Martín Lagos s/n. 28040 Madrid, Spain.
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Roncero O, Escribano G, Cigüenza Martín R. Síndrome constitucional con impotencia funcional de miembro inferior izquierdo en varón de 76 años. Rev Clin Esp 2001. [DOI: 10.1016/s0014-2565(01)70743-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Gadéa FX, Berriche H, Roncero O, Villarreal P, Delgado Barrio G. Nonradiative lifetimes for LiH in the A state using adiabatic and diabatic schemes. J Chem Phys 1997. [DOI: 10.1063/1.474215] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Roncero O, Delgado-Barrio G, Hernández M, Campos-Martínez J, Villarreal P. Wave packet study of the Ne2I2 fragmentation dynamics: a four degrees of freedom model. Chem Phys Lett 1995. [DOI: 10.1016/0009-2614(95)01087-p] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Beswick JA, Glass‐Maujean M, Roncero O. On the orientation of molecular photofragments produced in highly excited rotational states. J Chem Phys 1992. [DOI: 10.1063/1.462403] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Villarreal P, Miret‐Artés S, Roncero O, Delgado‐Barrio G, Beswick JA, Halberstadt N, Coalson RD. A wave packet Golden Rule treatment of vibrational predissociation. J Chem Phys 1991. [DOI: 10.1063/1.460631] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Gianturco F, Delgado-Barrio G, Roncero O, Villarreal P. Alternative decoupled representations for the dynamics of van der Waals molecules: a test for the He, Ne-O2systems. Mol Phys 1990. [DOI: 10.1080/00268979000102561] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Villarreal P, Miret‐Artés S, Roncero O, Serna S, Campos‐Martínez J, Delgado‐Barrio G. Double continuum fragmentation in the vibrational predissociation X⋅⋅⋅BC(v)⋅⋅⋅Y→BC(v’ J Chem Phys 1990. [DOI: 10.1063/1.458786] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Roncero O, Beswick JA, Halberstadt N, Villarreal P, Delgado‐Barrio G. Photofragmentation of the Ne⋅⋅⋅ICl complex: A three‐dimensional quantum mechanical study. J Chem Phys 1990. [DOI: 10.1063/1.458578] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Campos‐Martinez J, Roncero O, Miret‐Artés S, Villarreal P, Delgado‐Barrio G. Study of the electronic‐to‐vibrational energy transfer in the quenching process of Na*(3 2P) with N2(1Σ+g,v=0). A quantal close coupling calculation. J Chem Phys 1989. [DOI: 10.1063/1.457494] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Hernández M, Roncero O, Miret‐Artés S, Villarreal P, Delgado‐Barrio G. Study of the diffraction mediated selective adsorption through the close‐coupling and diabatic distorted wave formalisms. Application to the4He–Cu(110) system. J Chem Phys 1989. [DOI: 10.1063/1.455839] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Gianturco FA, Delgado-Barrio G, Roncero O, Villarreal P. Dynamical coupling and energy transfer in weakly bound molecular complexes. INT REV PHYS CHEM 1988. [DOI: 10.1080/01442358809353203] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Villarreal P, Delgado-Barrio G, Roncero O, Gianturco FA, Palma A. Rotational predissociation of strongly anisotropic van der Waals complexes: The He-CO example. Phys Rev A Gen Phys 1987; 36:617-624. [PMID: 9898904 DOI: 10.1103/physreva.36.617] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Gianturco FA, Palma A, Villarreal P, Delgado‐Barrio G, Roncero O. Rotational predissociation of (rare gas atom)–(slow rotating diatomic molecule) complexes. J Chem Phys 1987. [DOI: 10.1063/1.453338] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Roncero O, Miret‐Artés S, Delgado‐Barrio G, Villarreal P. Application of a diabatic distorted wave approximation to the study of X⋅ ⋅ ⋅H2 (X=He, Ne, Ar) van der Waals molecules. J Chem Phys 1986. [DOI: 10.1063/1.451152] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Serrano C, Roncero O, Mareca P, Villarreal P, Delgado-Barrio G. Applications of an adiabatic rotational model to the Ar…O2 van der Waals molecule. Chem Phys 1985. [DOI: 10.1016/0301-0104(85)80014-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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