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Quintas-Sánchez E, Dawes R, Lee K, McCarthy MC. Automated Construction of Potential Energy Surfaces Suitable to Describe van der Waals Complexes with Highly Excited Nascent Molecules: The Rotational Spectra of Ar-CS( v) and Ar-SiS( v). J Phys Chem A 2020; 124:4445-4454. [PMID: 32368913 DOI: 10.1021/acs.jpca.0c02685] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Some reactions produce extremely hot nascent products which nevertheless can form sufficiently long-lived van der Waals (vdW) complexes-with atoms or molecules from a bath gas-as to be observed via microwave spectroscopy. Theoretical calculations of such unbound resonance states can be much more challenging than ordinary bound-state calculations depending on the approach employed. One encounters not just the floppy, and perhaps multiwelled potential energy surface (PES) characteristic of vdWs complexes, but in addition, one must contend with excitation of the intramolecular modes and its corresponding influence on the PES. Straightforward computation of the (resonance) rovibrational levels of interest, involves the added complication of the unbound nature of the wave function, often treated with techniques such as introducing a complex absorbing potential. Here, we have demonstrated that a simplified approach of making a series of vibrationally effective PESs for the intermolecular coordinates-one for each reaction product vibrational quantum number of interest-can produce vdW levels for the complex with spectroscopic accuracy. This requires constructing a series of appropriately weighted lower-dimensional PESs for which we use our freely available PES-fitting code AUTOSURF. The applications of this study are the Ar-CS and Ar-SiS complexes, which are isovalent to Ar-CO and Ar-SiO, the latter of which we considered in a previously reported study. Using a series of vibrationally effective PESs, rovibrational levels and predicted microwave transition frequencies for both complexes were computed variationally. A series of shifting rotational transition frequencies were also computed as a function of the diatom vibrational quantum number. The predicted transitions were used to guide and inform an experimental effort to make complementary observations. Comparisons are given for the transitions that are within the range of the spectrometer and were successfully recorded. Calculations of the rovibrational level pattern agree to within 0.2% with experimental measurements.
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Affiliation(s)
- Ernesto Quintas-Sánchez
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, United States
| | - Richard Dawes
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, United States
| | - Kelvin Lee
- Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, United States
| | - Michael C McCarthy
- Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, United States.,School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138, United States
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McCarthy MC, Ndengué SA, Dawes R. The rotational spectrum and potential energy surface of the Ar–SiO complex. J Chem Phys 2018; 149:134308. [DOI: 10.1063/1.5048202] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Michael C. McCarthy
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, USA and School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138, USA
| | - Steve Alexandre Ndengué
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, USA
| | - Richard Dawes
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, USA
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Vanfleteren T, Földes T, Herman M, Liévin J, Loreau J, Coudert LH. Experimental and theoretical investigations of H 2O-Ar. J Chem Phys 2018; 147:014302. [PMID: 28688396 DOI: 10.1063/1.4990738] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have used continuous-wave cavity ring-down spectroscopy to record the spectrum of H2O-Ar in the 2OH excitation range of H2O. 24 sub-bands have been observed. Their rotational structure (Trot = 12 K) is analyzed and the lines are fitted separately for ortho and para species together with microwave and far infrared data from the literature, with a unitless standard deviation σ=0.98 and 1.31, respectively. Their vibrational analysis is supported by a theoretical input based on an intramolecular potential energy surface obtained through ab initio calculations and computation of the rotational energy of sub-states of the complex with the water monomer in excited vibrational states up to the first hexad. For the ground and (010) vibrational states, the theoretical results agree well with experimental energies and rotational constants in the literature. For the excited vibrational states of the first hexad, they guided the assignment of the observed sub-bands. The upper state vibrational predissociation lifetime is estimated to be 3 ns from observed spectral linewidths.
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Affiliation(s)
- Thomas Vanfleteren
- Service de Chimie Quantique et Photophysique, CP160/09, Faculté des Sciences, Université Libre de Bruxelles, 50, Ave., Roosevelt B-1050, Belgium
| | - Tomas Földes
- Service de Chimie Quantique et Photophysique, CP160/09, Faculté des Sciences, Université Libre de Bruxelles, 50, Ave., Roosevelt B-1050, Belgium
| | - Michel Herman
- Service de Chimie Quantique et Photophysique, CP160/09, Faculté des Sciences, Université Libre de Bruxelles, 50, Ave., Roosevelt B-1050, Belgium
| | - Jacques Liévin
- Service de Chimie Quantique et Photophysique, CP160/09, Faculté des Sciences, Université Libre de Bruxelles, 50, Ave., Roosevelt B-1050, Belgium
| | - Jérôme Loreau
- Service de Chimie Quantique et Photophysique, CP160/09, Faculté des Sciences, Université Libre de Bruxelles, 50, Ave., Roosevelt B-1050, Belgium
| | - Laurent H Coudert
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Université Paris-Sud, Université Paris-Saclay, F-91405 Orsay, France
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Abstract
A three-dimensional intermolecular potential energy surface of the Ar-CO complex has been determined by fitting most of the previously reported spectroscopic data, where observed transition frequencies by microwave, millimeter-wave, submillimeter-wave, and infrared spectroscopy were reproduced simultaneously within their experimental accuracies. A free rotor model Hamiltonian considering all the freedom of motions for an atom-diatom system was applied to calculate vibration-rotation energies. A three-dimensional potential energy surface obtained by ab initio calculations at the CCSD(T)-F12b/aug-cc-pV5Z level of theory was parameterized by a model function consisting of 46 parameters. They were used as initial values for the least-squares analysis of the experimental data. A total of 20 parameters were optimized to reproduce all the spectroscopic data.
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Affiliation(s)
- Yoshihiro Sumiyoshi
- Division of Pure and Applied Science, Graduate School of Science and Technology, Gunma University, 4-2 Aramaki, Maebashi, Gunma 371-8510, Japan
| | - Yasuki Endo
- Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan
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Lauzin C, Coudert LH, Herman M, Liévin J. Ab Initio Intermolecular Potential of Ar–C2H2 Refined Using High-Resolution Spectroscopic Data. J Phys Chem A 2013; 117:13767-74. [DOI: 10.1021/jp408013n] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Clément Lauzin
- Service
de Chimie quantique et Photophysique CP160/09, Faculté des
Sciences, Université Libre de Bruxelles (ULB), Av. Roosevelt,
50, B-1050 Bruxelles, Belgium
- Laboratorium
für Physikalisch Chemie, ETH Zürich, 8093 Zürich, Switzerland
| | - Laurent H. Coudert
- Laboratoire
Inter-universitaire des Systèmes Atmosphériques (LISA), UMR 7583 CNRS, Universités Paris Est Créteil et Paris Diderot, 61
Avenue du Général de Gaulle, 94010 Créteil Cedex, France
| | - Michel Herman
- Service
de Chimie quantique et Photophysique CP160/09, Faculté des
Sciences, Université Libre de Bruxelles (ULB), Av. Roosevelt,
50, B-1050 Bruxelles, Belgium
| | - Jacques Liévin
- Service
de Chimie quantique et Photophysique CP160/09, Faculté des
Sciences, Université Libre de Bruxelles (ULB), Av. Roosevelt,
50, B-1050 Bruxelles, Belgium
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Feng E, Zhang Y, Wang Z, Niu M, Cui Z. Rovibrational structure of the Xe-CO complex based on a new three-dimensional ab initio potential. J Chem Phys 2009; 130:124311. [PMID: 19334834 DOI: 10.1063/1.3100754] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The first three-dimensional interaction potential energy surface of the Xe-CO complex is developed using the single and double excitation coupled cluster theory with noniterative treatment of triple excitations. Mixed basis sets, aug-cc-pVQZ for the C and O atoms and aug-cc-pVQZ-PP for the Xe atom, including an additional (3s3p2d2f1g) set of midbond functions are used. The calculated single point energies at five fixed r(co) values are fitted to an analytic two-dimensional potential model, and further the five model potentials are used to construct the three-dimensional potential energy surface by interpolating along (r-r(e)). Dynamical calculations with the vibrationally averaged potentials are performed to determine the energy levels and the frequencies of various rovibrational transitions. Our results agree well with the experiment. For example, the IR transitions of 508 lines are precisely reproduced with only a total rms error of 0.105 cm(-1).
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Affiliation(s)
- Eryin Feng
- Department of Physics, Anhui Normal University, Wuhu 241000, People's Republic of China.
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Surin L, Potapov A, Müller H, Panfilov V, Dumesh B, Giesen T, Schlemmer S. Millimeter-wave study of the CO–N2 van der Waals complex: new measurements of CO–orthoN2 and assignments of new states of CO–paraN2. J Mol Struct 2006. [DOI: 10.1016/j.molstruc.2006.02.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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