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Chang Z, Satija A, Lucht RP. Two-color polarization spectroscopy measurements of Zeeman state-to-state collision induced transitions of nitric oxide in binary gas mixtures. J Chem Phys 2023; 159:244309. [PMID: 38153153 DOI: 10.1063/5.0177626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 12/05/2023] [Indexed: 12/29/2023] Open
Abstract
We investigated collision induced transitions in the (0, 0) band of the A2Σ+-X2Π electronic transition of nitric oxide (NO) using two-color polarization spectroscopy (TCPS). Two sets of TCPS spectra for 1% NO, diluted in different buffer gases at 295 K and 1 atm, were obtained with the pump beam tuned to the R11(11.5) and OP12(1.5) transitions. The buffer gases were He, Ar, and N2. The probe was scanned while the pump beam was tuned to the line center. Theoretical TCPS spectra, calculated by solving the density matrix formulation of the time-dependent Schrödinger wave equation, were compared with the experimental spectra. A collision model based on the modified exponential-gap law was used to model the rotational level-to-rotational level collision dynamics. A model for collisional transfer from an initial to a final Zeeman state was developed based on the difference in cosine of the rotational quantum number J projection angle with the z-axis for the two Zeeman states. Rotational energy transfer rates and Zeeman state collisional dynamics were varied to obtain good agreement between theory and experiment for the two different TCPS pump transitions and for the three different buffer gases. One key finding, in agreement with quasi-classical trajectory calculations, is that the spin-rotation changing transition rate in the A2Σ+ level of NO is almost zero for rotational quantum numbers ≥8. It was necessary to set this rate to near zero to obtain agreement with the TCPS spectra.
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Affiliation(s)
- Ziqiao Chang
- School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, USA
| | - Aman Satija
- School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, USA
| | - Robert P Lucht
- School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, USA
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2
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Mandal A, Hunt KLC. Quantum transition probabilities due to overlapping electromagnetic pulses: Persistent differences between Dirac's form and nonadiabatic perturbation theory. J Chem Phys 2021; 154:024116. [PMID: 33445917 DOI: 10.1063/5.0020169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The probability of transition to an excited state of a quantum system in a time-dependent electromagnetic field determines the energy uptake from the field. The standard expression for the transition probability has been given by Dirac. Landau and Lifshitz suggested, instead, that the adiabatic effects of a perturbation should be excluded from the transition probability, leaving an expression in terms of the nonadiabatic response. In our previous work, we have found that these two approaches yield different results while a perturbing field is acting on the system. Here, we prove, for the first time, that differences between the two approaches may persist after the perturbing fields have been completely turned off. We have designed a pair of overlapping pulses in order to establish the possibility of lasting differences, in a case with dephasing. Our work goes beyond the analysis presented by Landau and Lifshitz, since they considered only linear response and required that a constant perturbation must remain as t → ∞. First, a "plateau" pulse populates an excited rotational state and produces coherences between the ground and excited states. Then, an infrared pulse acts while the electric field of the first pulse is constant, but after dephasing has occurred. The nonadiabatic perturbation theory permits dephasing, but dephasing of the perturbed part of the wave function cannot occur within Dirac's method. When the frequencies in both pulses are on resonance, the lasting differences in the calculated transition probabilities may exceed 35%. The predicted differences are larger for off-resonant perturbations.
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Affiliation(s)
- Anirban Mandal
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - Katharine L C Hunt
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
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3
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Price TJ, Hickman AP. Semiclassical analysis of jm → j'm' transitions in rotationally inelastic collisions in cell experiments. J Chem Phys 2018; 148:074105. [PMID: 29471636 DOI: 10.1063/1.4996877] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Recent quantum calculations of rotationally inelastic collisions of NaK (A1Σ+) with He or Ar in a cell experiment are analyzed using semiclassical approximations valid for large quantum numbers. The results suggest a physical interpretation of jm → j'm' transitions based on the vector model and lead to expressions that explicitly involve the initial and final polar angles of the angular momentum of the target molecule. The relation between the polar angle θ and the azimuthal quantum number m links the semiclassical results for the change in polar angle (θ → θ') to quantum results for an m → m' transition. Analytic formulas are derived that relate the location and width of peaks in the final polar angle distribution (PAD) to the K-dependence of the coefficients dK(j, j'), which are proportional to tensor cross sections σK(j → j'). Several special cases are treated that lead to final PADs that are approximately Lorentzian or sinc functions centered at θ' = θ. Another interesting case, "angular momentum reversal," was observed in the calculations for He. This phenomenon, which involves a reversal of the direction of the target's angular momentum, is shown to be associated with oscillatory behavior of the dK for certain transitions. Finally, several strategies for obtaining the dK coefficients from experimental data are discussed.
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Affiliation(s)
- T J Price
- Department of Physics, Lehigh University, 16 Memorial Drive East, Bethlehem, Pennsylvania 18015, USA
| | - A P Hickman
- Department of Physics, Lehigh University, 16 Memorial Drive East, Bethlehem, Pennsylvania 18015, USA
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4
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Brouard M, Lawlor J, McCrudden G, Perkins T, Seamons SA, Stevenson P, Chadwick H, Aoiz FJ. An experimental study of OH(A 2Σ +) + H 2: Electronic quenching, rotational energy transfer, and collisional depolarization. J Chem Phys 2017; 146:244313. [PMID: 28668067 DOI: 10.1063/1.4989567] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Zeeman quantum beat spectroscopy has been used to determine the thermal (300 K) rate constants for electronic quenching, rotational energy transfer, and collisional depolarization of OH(A2Σ+) by H2. Cross sections for both the collisional disorientation and collisional disalignment of the angular momentum in the OH(A2Σ+) radical are reported. The experimental results for OH(A2Σ+) + H2 are compared to previous work on the OH(A2Σ+) + He and Ar systems. Further comparisons are also made to the OH(A2Σ+) + Kr system, which has been shown to display significant non-adiabatic dynamics. The OH(A2Σ+) + H2 experimental data reveal that collisions that survive the electronic quenching process are highly depolarizing, reflecting the deep potential energy wells that exist on the excited electronic state surface.
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Affiliation(s)
- M Brouard
- Chemistry Research Laboratory, The Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - J Lawlor
- Chemistry Research Laboratory, The Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - G McCrudden
- Chemistry Research Laboratory, The Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - T Perkins
- Chemistry Research Laboratory, The Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - S A Seamons
- Chemistry Research Laboratory, The Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - P Stevenson
- Chemistry Research Laboratory, The Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - H Chadwick
- Chemistry Research Laboratory, The Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - F J Aoiz
- Departamento de Química Física, Facultad de Química, Universidad Complutense, 28040 Madrid, Spain
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5
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Lemeshko M. Quasiparticle Approach to Molecules Interacting with Quantum Solvents. PHYSICAL REVIEW LETTERS 2017; 118:095301. [PMID: 28306270 DOI: 10.1103/physrevlett.118.095301] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Indexed: 06/06/2023]
Abstract
Understanding the behavior of molecules interacting with superfluid helium represents a formidable challenge and, in general, requires approaches relying on large-scale numerical simulations. Here, we demonstrate that experimental data collected over the last 20 years provide evidence that molecules immersed in superfluid helium form recently predicted angulon quasiparticles [Phys. Rev. Lett. 114, 203001 (2015)PRLTAO0031-900710.1103/PhysRevLett.114.203001]. Most important, casting the many-body problem in terms of angulons amounts to a drastic simplification and yields effective molecular moments of inertia as straightforward analytic solutions of a simple microscopic Hamiltonian. The outcome of the angulon theory is in good agreement with experiment for a broad range of molecular impurities, from heavy to medium-mass to light species. These results pave the way to understanding molecular rotation in liquid and crystalline phases in terms of the angulon quasiparticle.
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Affiliation(s)
- Mikhail Lemeshko
- IST Austria (Institute of Science and Technology Austria), Am Campus 1, 3400 Klosterneuburg, Austria and Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106, USA
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6
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Price T, Towne A, Talbi D, Hickman A. Semiclassical model for the distribution of final polar angles and m′ states in rotationally inelastic collisions. Chem Phys Lett 2016. [DOI: 10.1016/j.cplett.2015.12.037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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7
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Sharples TR, Luxford TFM, Townsend D, McKendrick KG, Costen ML. Rotationally inelastic scattering of NO(A(2)Σ(+)) + Ar: Differential cross sections and rotational angular momentum polarization. J Chem Phys 2015; 143:204301. [PMID: 26627953 DOI: 10.1063/1.4935962] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present the implementation of a new crossed-molecular beam, velocity-map ion-imaging apparatus, optimized for collisions of electronically excited molecules. We have applied this apparatus to rotational energy transfer in NO(A(2)Σ(+), v = 0, N = 0, j = 0.5) + Ar collisions, at an average energy of 525 cm(-1). We report differential cross sections for scattering into NO(A(2)Σ(+), v = 0, N' = 3, 5, 6, 7, 8, and 9), together with quantum scattering calculations of the differential cross sections and angle dependent rotational alignment. The differential cross sections show dramatic forward scattered peaks, together with oscillatory behavior at larger scattering angles, while the rotational alignment moments are also found to oscillate as a function of scattering angle. In general, the quantum scattering calculations are found to agree well with experiment, reproducing the forward scattering and oscillatory behavior at larger scattering angles. Analysis of the quantum scattering calculations as a function of total rotational angular momentum indicates that the forward scattering peak originates from the attractive minimum in the potential energy surface at the N-end of the NO. Deviations in the quantum scattering predictions from the experimental results, for scattering at angles greater than 10°, are observed to be more significant for scattering to odd final N'. We suggest that this represents inaccuracies in the potential energy surface, and in particular in its representation of the difference between the N- and O-ends of the molecule, as given by the odd-order Legendre moments of the surface.
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Affiliation(s)
- Thomas R Sharples
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Thomas F M Luxford
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Dave Townsend
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Kenneth G McKendrick
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Matthew L Costen
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
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8
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Malenda RF, Price TJ, Stevens J, Uppalapati SL, Fragale A, Weiser PM, Kuczala A, Talbi D, Hickman AP. Theoretical calculations of rotationally inelastic collisions of He with NaK(A (1)Σ(+)): Transfer of population, orientation, and alignment. J Chem Phys 2015; 142:224301. [PMID: 26071704 DOI: 10.1063/1.4922161] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We have performed extensive calculations to investigate thermal energy, rotationally inelastic collisions of NaK (A(1)Σ(+)) with He. We determined a potential energy surface using a multi-reference configuration interaction wave function as implemented by the GAMESS electronic structure code, and we have performed coupled channel scattering calculations using the Arthurs and Dalgarno formalism. We also calculate the Grawert coefficients B(λ)(j, j') for each j → j' transition. These coefficients are used to determine the probability that orientation and alignment are preserved in collisions taking place in a cell environment. The calculations include all rotational levels with j or j' between 0 and 50, and total (translational and rotational) energies in the range 0.0002-0.0025 a.u. (∼44-550 cm(-1)). The calculated cross sections for transitions with even values of Δj tend to be larger than those for transitions with odd Δj, in agreement with the recent experiments of Wolfe et al. (J. Chem. Phys. 134, 174301 (2011)). The calculations of the energy dependence of the cross sections and the calculations of the fraction of orientation and alignment preserved in collisions also exhibit distinctly different behaviors for odd and even values of Δj. The calculations also indicate that the average fraction of orientation or alignment preserved in a transition becomes larger as j increases. We interpret this behavior using the semiclassical model of Derouard, which also leads to a simple way of visualizing the distribution of the angles between the initial and final angular momentum vectors j and j'. Finally, we compare the exact quantum results for j → j' transitions with results based on the simpler, energy sudden approximation. That approximation is shown to be quite accurate.
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Affiliation(s)
- R F Malenda
- Department of Physics, Lehigh University, 16 Memorial Dr. East, Bethlehem, Pennsylvania 18015, USA
| | - T J Price
- Department of Physics, Lehigh University, 16 Memorial Dr. East, Bethlehem, Pennsylvania 18015, USA
| | - J Stevens
- Department of Physics, Lehigh University, 16 Memorial Dr. East, Bethlehem, Pennsylvania 18015, USA
| | - S L Uppalapati
- Department of Physics, Lehigh University, 16 Memorial Dr. East, Bethlehem, Pennsylvania 18015, USA
| | - A Fragale
- Department of Physics, Lehigh University, 16 Memorial Dr. East, Bethlehem, Pennsylvania 18015, USA
| | - P M Weiser
- Department of Physics, Lehigh University, 16 Memorial Dr. East, Bethlehem, Pennsylvania 18015, USA
| | - A Kuczala
- Department of Physics, Lehigh University, 16 Memorial Dr. East, Bethlehem, Pennsylvania 18015, USA
| | - D Talbi
- Laboratoire Univers et Particules de Montpellier, UMR 5299, Université Montpellier, Place Eugène Bataillon, 34095 Montpellier, France
| | - A P Hickman
- Department of Physics, Lehigh University, 16 Memorial Dr. East, Bethlehem, Pennsylvania 18015, USA
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9
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Sarma G, Saha AK, ter Meulen JJ, Parker DH, Marinakis S. Differential and integral cross sections in OH(X) + Xe collisions. J Chem Phys 2015; 142:034309. [PMID: 25612711 DOI: 10.1063/1.4906070] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Differential cross sections (DCSs) for inelastic collisions of OH(X) with Xe have been measured at a collision energy of 483 cm(-1). The hydroxyl (OH) radicals were initially prepared in the X(2)Π3/2 (v = 0, j = 1.5, f) level using the hexapole electric field selection method. Products were detected state-selectively by [2 + 1] resonance-enhanced multiphoton ionization of OH, combined with velocity-map imaging. Integral cross sections in OH(X) + Xe at a collision energy of 490 cm(-1) were also measured by laser-induced fluorescence. The results are compared with exact close-coupling quantum mechanical scattering calculations on the only available ab initio potential energy surface (PES). The agreement between experimental and theoretical results is generally very satisfactory. This highlights the ability of such measurements to test the available PES for such a benchmark open-shell system. The agreement between experiment and theory for DCSs is less satisfactory at low scattering angles, and possible reasons for this disagreement are discussed. Finally, theoretical calculations of OH(X) + He DCSs have been obtained at various collision energies and are compared with those of OH(X) + Xe. The role of the reduced mass in the DCSs and partial cross sections is also examined.
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Affiliation(s)
- Gautam Sarma
- Institute for Molecules and Materials, Radboud University Nijmegen, Heijendaalseweg 135, 6525 ED Nijmegen, The Netherlands
| | - Ashim Kumar Saha
- Institute for Molecules and Materials, Radboud University Nijmegen, Heijendaalseweg 135, 6525 ED Nijmegen, The Netherlands
| | - J J ter Meulen
- Institute for Molecules and Materials, Radboud University Nijmegen, Heijendaalseweg 135, 6525 ED Nijmegen, The Netherlands
| | - David H Parker
- Institute for Molecules and Materials, Radboud University Nijmegen, Heijendaalseweg 135, 6525 ED Nijmegen, The Netherlands
| | - Sarantos Marinakis
- School of Biological and Chemical Sciences, Queen Mary University of London, Joseph Priestley Building, Mile End Road, London E1 4NS, United Kingdom
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10
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Tkáč O, Ma Q, Stei M, Orr-Ewing AJ, Dagdigian PJ. Rotationally inelastic scattering of methyl radicals with Ar and N2. J Chem Phys 2015; 142:014306. [PMID: 25573560 DOI: 10.1063/1.4904901] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The rotationally inelastic scattering of methyl radical with Ar and N2 is examined at collision energies of 330 ± 25 cm(-1) and 425 ± 50 cm(-1), respectively. Differential cross sections (DCSs) were measured for different final n' rotational levels (up to n' = 5) of the methyl radicals, averaged over k' sub-levels, using a crossed molecular beam machine with velocity map imaging. For Ar as a collision partner, we present a newly constructed ab initio potential energy surface and quantum mechanical scattering calculations of state-resolved DCSs. These computed DCSs agree well with the measurements. The DCSs for both Ar and N2 collision partners are strongly forward peaked for all spectroscopic lines measured. For scattering angles below 60°, the theoretical CD3-Ar DCSs show diffraction oscillations that become less pronounced as n' increases, but these oscillations are not resolved experimentally. Comparisons are drawn with our recently reported DCSs for scattering of methyl radicals with He atoms.
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Affiliation(s)
- Ondřej Tkáč
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Qianli Ma
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218-2685, USA
| | - Martin Stei
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Andrew J Orr-Ewing
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Paul J Dagdigian
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218-2685, USA
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11
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Tkáč O, Rusher CA, Greaves SJ, Orr-Ewing AJ, Dagdigian PJ. Differential and integral cross sections for the rotationally inelastic scattering of methyl radicals with H2and D2. J Chem Phys 2014; 140:204318. [DOI: 10.1063/1.4879618] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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12
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Chadwick H, Brouard M, Perkins T, Aoiz F. Collisional depolarisation in electronically excited radicals. INT REV PHYS CHEM 2014. [DOI: 10.1080/0144235x.2014.891855] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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13
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Chadwick H, Brouard M, Chang YP, Eyles CJ, McCrudden G, Perkins T, Seamons SA, Kłos J, Alexander MH, Dagdigian PJ, Herráez-Aguilar D, Aoiz FJ. The collisional depolarization of OH(A 2Σ+) and NO(A 2Σ+) with Kr. J Chem Phys 2014; 140:054306. [DOI: 10.1063/1.4863446] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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14
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Kalugina Y, Lique F, Marinakis S. New ab initio potential energy surfaces for the ro-vibrational excitation of OH(X2Π) by He. Phys Chem Chem Phys 2014; 16:13500-7. [DOI: 10.1039/c4cp01473a] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A new, three-dimensional potential energy is presented. Values for integral and differential cross sections, and for inelastic rate coefficients were obtained. The results agree and significantly extend previous studies on OH(X) + He collisions.
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Affiliation(s)
- Yulia Kalugina
- LOMC – UMR 6294
- CNRS-Université du Havre
- Le Havre, France
- Tomsk State University
- Tomsk 634050, Russia
| | | | - Sarantos Marinakis
- School of Biological and Chemical Sciences
- Queen Mary University of London
- London E1 4NS, UK
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15
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McGurk SJ, McKendrick KG, Costen ML, Alexander MH, Dagdigian PJ. Parity-dependent oscillations in collisional polarization transfer: CN(A²Π, v = 4) + Ar. J Chem Phys 2013; 139:124304. [PMID: 24089764 DOI: 10.1063/1.4821602] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report the first systematic experimental and theoretical study of the state-to-state transfer of rotational angular momentum orientation in a (2)Π-rare gas system. CN(X(2)Σ(+)) was produced by pulsed 266 nm photolysis of ICN in a thermal bath (296 K) of Ar collider gas. A pulsed circularly polarized tunable dye laser prepared CN(A(2)Π, v = 4) in two fully state-selected initial levels, j = 6.5 F1e and j = 10.5 F2f, with a known laboratory-frame orientation. Both the prepared levels and a range of product levels, j' F1e and j' F2f, were monitored using the circular polarized output of a tunable diode laser via cw frequency-modulated (FM) spectroscopy in stimulated emission on the CN(A-X) (4,2) band. The FM Doppler lineshapes for co-rotating and counter-rotating pump-and-probe geometries reveal the time-dependence of the populations and orientations. Kinetic fitting was used to extract the state-to-state population transfer rate constants and orientation multipole transfer efficiencies (MTEs), which quantify the degree of conservation of initially prepared orientation in the product level. Complementary full quantum scattering (QS) calculations were carried out on recently computed ab initio potential energy surfaces. Collision-energy-dependent tensor cross sections for ranks K = 0 and 1 were computed for transitions from both initial levels to all final levels. These quantities were integrated over the thermal collision energy distribution to yield predictions of the experimentally observed state-to-state population transfer rate constants and MTEs. Excellent agreement between experiment and theory is observed for both measured quantities. Dramatic oscillations in the MTEs are observed, up to and including changes in the sign of the orientation, as a function of even/odd Δj within a particular spin-orbit and e/f manifold. These oscillations, along with those also observed in the state-to-state rate constants, reflect the rotational parity of the final level. In general, parity-conserving collisions conserve rotational orientation, while parity-changing collisions result in large changes in the orientation. The QS calculations show that the dynamics of the collisions leading to these different outcomes are fundamentally different. We propose that the origin of this behavior lies in interferences between collisions that sample the even and odd-λ terms in the angular expansions of the PESs.
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Affiliation(s)
- S J McGurk
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
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16
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Hapka M, Żuchowski PS, Szczęśniak MM, Chałasiński G. Symmetry-adapted perturbation theory based on unrestricted Kohn-Sham orbitals for high-spin open-shell van der Waals complexes. J Chem Phys 2013; 137:164104. [PMID: 23126692 DOI: 10.1063/1.4758455] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Two open-shell formulations of the symmetry-adapted perturbation theory are presented. They are based on the spin-unrestricted Kohn-Sham (SAPT(UKS)) and unrestricted Hartree-Fock (SAPT(UHF)) descriptions of the monomers, respectively. The key reason behind development of SAPT(UKS) is that it is more compatible with density functional theory (DFT) compared to the previous formulation of open-shell SAPT based on spin-restricted Kohn-Sham method of Żuchowski et al. [J. Chem. Phys. 129, 084101 (2008)]. The performance of SAPT(UKS) and SAPT(UHF) is tested for the following open-shell van der Waals complexes: He···NH, H(2)O···HO(2), He···OH, Ar···OH, Ar···NO. The results show an excellent agreement between SAPT(UKS) and SAPT(ROKS). Furthermore, for the first time SAPT based on DFT is shown to be suitable for the treatment of interactions involving Π-state radicals (He···OH, Ar···OH, Ar···NO). In the interactions of transition metal dimers ((3)Σ(u)(+))Au(2) and ((13)Σ(g)(+))Cr(2) we show that SAPT is incompatible with the use of effective core potentials. The interaction energies of both systems expressed instead as supermolecular UHF interaction plus dispersion from SAPT(UKS) result in reasonably accurate potential curves.
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Affiliation(s)
- Michał Hapka
- Faculty of Chemistry, University of Warsaw, 02-093 Warsaw, Pasteura 1, Poland.
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17
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Tkáč O, Sage AG, Greaves SJ, Orr-Ewing AJ, Dagdigian PJ, Ma Q, Alexander MH. Rotationally inelastic scattering of CD3 and CH3 with He: comparison of velocity map-imaging data with quantum scattering calculations. Chem Sci 2013. [DOI: 10.1039/c3sc52002a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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18
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19
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Inelastic scattering of hydroxyl radicals with helium and argon by velocity-map imaging. Nat Chem 2012; 4:985-9. [DOI: 10.1038/nchem.1480] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 09/20/2012] [Indexed: 11/08/2022]
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20
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Jambrina PG, Kłos J, Aoiz FJ, de Miranda MP. New findings regarding the NO angular momentum orientation in Ar-NO(2Π(1/2)) collisions. Phys Chem Chem Phys 2012; 14:9826-37. [PMID: 22710404 DOI: 10.1039/c2cp41043e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This article reports a theoretical study of the stereodynamics of Ar + NO(X(2)Π, v = 0, j = 1/2, Ω = 1/2, ε = ±1) rotationally inelastic collisions. First, quantum scattering data are used to calculate all differential polarisation moments of the reagent and product molecules; this leads to the observation that the orientations of the reagent and product angular momenta are very strongly correlated. Next, canonical collision mechanisms theory [Aldegunde et al., Phys. Chem. Chem. Phys., 2008, 10, 1139] is used to separate and characterise the stereodynamics of the two independent collision mechanisms that contribute to the collision dynamics; this leads to the observation that the average product orientation is determined by the relative contributions of the two canonical mechanisms, which have comparable importance but are associated with starkly contrasting angular momentum orientations. These observations lead to a new and rigorous explanation of the experimental results reported a decade ago by Lorenz et al. [Science, 2001, 293, 2063]. The central fact of the new explanation is the incoherent, interference-free superposition of two independent collision mechanisms. This makes the new explanation radically different from the only one previously suggested, namely that the experimental observations might be due to quantum interference in a single collision mechanism.
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Affiliation(s)
- Pablo G Jambrina
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad de Salamanca, 37008 Salamanca, Spain
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McGurk SJ, McKendrick KG, Costen ML, Bennett DIG, Kłos J, Alexander MH, Dagdigian PJ. Depolarization of rotational angular momentum in CN(A2Π, v = 4) + Ar collisions. J Chem Phys 2012; 136:164306. [PMID: 22559481 DOI: 10.1063/1.4705118] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Angular momentum depolarization and population transfer in CN(A(2)Π, v = 4, j, F(1)e) + Ar collisions have been investigated both experimentally and theoretically. Ground-state CN(X(2)Σ(+)) molecules were generated by pulsed 266-nm laser photolysis of ICN in a thermal (nominally 298 K) bath of the Ar collision partner at a range of pressures. The translationally thermalized CN(X) radicals were optically pumped to selected unique CN(A(2)Π, v = 4, j = 2.5, 3.5, 6.5, 11.5, 13.5, and 18.5, F(1)e) levels on the A-X (4,0) band by a pulsed tunable dye laser. The prepared level was monitored in a collinear geometry by cw frequency-modulated (FM) spectroscopy in stimulated emission on the CN(A-X) (4,2) band. The FM lineshapes for co- and counter-rotating circular pump and probe polarizations were analyzed to extract the time dependence of the population and (to a good approximation) orientation (tensor rank K = 1 polarization). The corresponding parallel and perpendicular linear polarizations yielded population and alignment (K = 2). The combined population and polarization measurements at each Ar pressure were fitted to a 3-level kinetic model, the minimum complexity necessary to reproduce the qualitative features of the data. Rate constants were extracted for the total loss of population and of elastic depolarization of ranks K = 1 and 2. Elastic depolarization is concluded to be a relatively minor process in this system. Complementary full quantum scattering (QS) calculations were carried out on the best previous and a new set of ab initio potential energy surfaces for CN(A)-Ar. Collision-energy-dependent elastic tensor and depolarization cross sections for ranks K = 1 and 2 were computed for CN(A(2)Π, v = 4, j = 1.5-10.5, F(1)e) rotational/fine-structure levels. In addition, integral cross sections for rotationally inelastic transitions out of these levels were computed and summed to yield total population transfer cross sections. These quantities were integrated over a thermal collision-energy distribution to yield the corresponding rate constants. A complete master-equation simulation using the QS results for the selected initial level j = 6.5 gave close, but not perfect, agreement with the near-exponential experimental population decays, and successfully reproduced the observed multimodal character of the polarization decays. On average, the QS population removal rate constants were consistently 10%-15% higher than those derived from the 3-level fit to the experimental data. The QS and experimental depolarization rate constants agree within the experimental uncertainties at low j, but the QS predictions decline more rapidly with j than the observations. In addition to providing a sensitive test of the achievable level of agreement between state-of-the art experiment and theory, these results highlight the importance of multiple collisions in contributing to phenomenological depolarization using any method sensitive to both polarized and unpolarized molecules in the observed level.
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Affiliation(s)
- S J McGurk
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
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Paterson G, Costen ML, McKendrick KG. Collisional depolarisation of rotational angular momentum: influence of the potential energy surface on the collision dynamics? INT REV PHYS CHEM 2012. [DOI: 10.1080/0144235x.2012.659046] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Paterson G, Relf A, Costen ML, McKendrick KG, Alexander MH, Dagdigian PJ. Rotationally elastic and inelastic dynamics of NO(X2Π, v = 0) in collisions with Ar. J Chem Phys 2011; 135:234304. [PMID: 22191872 DOI: 10.1063/1.3665135] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A combined theoretical and experimental study of the depolarization of selected NO(X(2)Π, v = 0, j, F, ɛ) levels in collisions with a thermal bath of Ar has been carried out. Rate constants for elastic depolarization of rank K = 1 (orientation) and K = 2 (alignment) were extracted from collision-energy-dependent quantum scattering calculations, along with those for inelastic population transfer to discrete product levels. The rate constants for total loss of polarization of selected initial levels, which are the sum of elastic depolarization and population transfer contributions, were measured using a two-color polarization spectroscopy technique. Theory and experiment agree qualitatively that the rate constants for total loss of polarization decline modestly with j, but the absolute values differ by significantly more than the statistical uncertainties in the measurements. The reasons for this discrepancy are as yet unclear. The lack of a significant K dependence in the experimental data is, however, consistent with the theoretical prediction that elastic depolarization makes only a modest contribution to the total loss of polarization. This supports a previous conclusion that elastic depolarization for NO(X(2)Π) + Ar is significantly less efficient than for the electronically closely related system OH(X(2)Π) + Ar [P. J. Dagdigian and M. H. Alexander, J. Chem. Phys. 130, 204304 (2009)].
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Affiliation(s)
- G Paterson
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, United Kingdom
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Paterson G, Costen ML, McKendrick KG. Collisional depolarization of rotational angular momentum: what are the observables and how can they be measured? Mol Phys 2011. [DOI: 10.1080/00268976.2011.621901] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Brouard M, Chadwick H, Chang YP, Eyles CJ, Aoiz FJ, Kłos J. Collisional angular momentum depolarization of OH(A) and NO(A) by Ar: A comparison of mechanisms. J Chem Phys 2011; 135:084306. [DOI: 10.1063/1.3625638] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Brouard M, Chadwick H, Eyles CJ, Aoiz FJ, Kłos J. The k-j-j′ vector correlation in inelastic and reactive scattering. J Chem Phys 2011; 135:084305. [DOI: 10.1063/1.3625637] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Wolfe CM, Ashman S, Bai J, Beser B, Ahmed EH, Lyyra AM, Huennekens J. Collisional transfer of population and orientation in NaK. J Chem Phys 2011; 134:174301. [PMID: 21548681 DOI: 10.1063/1.3575234] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Collisional satellite lines with |ΔJ| ≤ 58 have been identified in recent polarization spectroscopy V-type optical-optical double resonance (OODR) excitation spectra of the Rb(2) molecule [H. Salami et al., Phys. Rev. A 80, 022515 (2009)]. Observation of these satellite lines clearly requires a transfer of population from the rotational level directly excited by the pump laser to a neighboring level in a collision of the molecule with an atomic perturber. However to be observed in polarization spectroscopy, the collision must also partially preserve the angular momentum orientation, which is at least somewhat surprising given the extremely large values of ΔJ that were observed. In the present work, we used the two-step OODR fluorescence and polarization spectroscopy techniques to obtain quantitative information on the transfer of population and orientation in rotationally inelastic collisions of the NaK molecules prepared in the 2(A)(1)Σ(+)(v' = 16, J' = 30) rovibrational level with argon and potassium perturbers. A rate equation model was used to study the intensities of these satellite lines as a function of argon pressure and heat pipe oven temperature, in order to separate the collisional effects of argon and potassium atoms. Using a fit of this rate equation model to the data, we found that collisions of NaK molecules with potassium atoms are more likely to transfer population and destroy orientation than collisions with argon atoms. Collisions with argon atoms show a strong propensity for population transfer with ΔJ = even. Conversely, collisions with potassium atoms do not show this ΔJ = even propensity, but do show a propensity for ΔJ = positive compared to ΔJ = negative, for this particular initial state. The density matrix equations of motion have also been solved numerically in order to test the approximations used in the rate equation model and to calculate fluorescence and polarization spectroscopy line shapes. In addition, we have measured rate coefficients for broadening of NaK 3(1)Π ← 2(A)(1)Σ(+)spectral lines due to collisions with argon and potassium atoms. Additional broadening, due to velocity changes occurring in rotationally inelastic collisions, has also been observed.
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Affiliation(s)
- C M Wolfe
- Department of Physics, Lehigh University, Bethlehem, Pennsylvania 18015, USA
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Ma L, Alexander MH, Dagdigian PJ. Theoretical investigation of rotationally inelastic collisions of CH2(ã) with helium. J Chem Phys 2011; 134:154307. [DOI: 10.1063/1.3575200] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Waring C, King KL, Bagot PAJ, Costen ML, McKendrick KG. Collision dynamics and reactive uptake of OH radicals at liquid surfaces of atmospheric interest. Phys Chem Chem Phys 2011; 13:8457-69. [DOI: 10.1039/c0cp02734k] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Owschimikow N, Königsmann F, Maurer J, Giese P, Ott A, Schmidt B, Schwentner N. Cross sections for rotational decoherence of perturbed nitrogen measured via decay of laser-induced alignment. J Chem Phys 2010; 133:044311. [DOI: 10.1063/1.3464487] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Ballingall I, Rutherford MF, McKendrick KG, Costen ML. Elastic depolarization and polarization transfer in CN(A2Π,v= 4)+Ar collisions. Mol Phys 2010. [DOI: 10.1080/00268970903476670] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Scharfenberg L, Kłos J, Dagdigian PJ, Alexander MH, Meijer G, van de Meerakker SYT. State-to-state inelastic scattering of Stark-decelerated OH radicals with Ar atoms. Phys Chem Chem Phys 2010; 12:10660-70. [DOI: 10.1039/c004422a] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Dagdigian PJ, Alexander MH. Erratum: “Tensor cross sections and the collisional evolution of state multipoles: OH(X Π2)–Ar” [J. Chem. Phys. 130, 094303 (2009)]. J Chem Phys 2009. [DOI: 10.1063/1.3271997] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Paterson G, Marinakis S, Costen ML, McKendrick KG, Kłos J, Toboła R. Erratum: “Orientation and alignment depolarization in OH(X 2Π)+Ar/He collisions” [J. Chem. Phys. 129, 074304 (2008)]. J Chem Phys 2009; 131:159901. [DOI: 10.1063/1.3243457] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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Costen ML, Livingstone R, McKendrick KG, Paterson G, Brouard M, Chadwick H, Chang YP, Eyles CJ, Aoiz FJ, Kłos J. Elastic Depolarization of OH(A) by He and Ar: A Comparative Study. J Phys Chem A 2009; 113:15156-70. [DOI: 10.1021/jp905348c] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | | | | | | | | | | | - F. J. Aoiz
- Departamento de Química Física, Facultad de Química, Universidad Complutense, 28040 Madrid, Spain
| | - J. Kłos
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742
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Pavlovic Z, Tscherbul TV, Sadeghpour HR, Groenenboom GC, Dalgarno A. Cold Collisions of OH(2Π) Molecules with He Atoms in External Fields. J Phys Chem A 2009; 113:14670-80. [DOI: 10.1021/jp904512r] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Z. Pavlovic
- ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, Department of Physics, University of Connecticut, Storrs, Connecticut 06269, Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, and Theoretical Chemistry, Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - T. V. Tscherbul
- ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, Department of Physics, University of Connecticut, Storrs, Connecticut 06269, Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, and Theoretical Chemistry, Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - H. R. Sadeghpour
- ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, Department of Physics, University of Connecticut, Storrs, Connecticut 06269, Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, and Theoretical Chemistry, Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - G. C. Groenenboom
- ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, Department of Physics, University of Connecticut, Storrs, Connecticut 06269, Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, and Theoretical Chemistry, Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - A. Dalgarno
- ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, Department of Physics, University of Connecticut, Storrs, Connecticut 06269, Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, and Theoretical Chemistry, Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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Dagdigian PJ, Alexander MH. Dependence of elastic depolarization cross sections on the potential: OH(X 2Pi)-Ar and NO(X 2Pi)-Ar. J Chem Phys 2009; 130:204304. [PMID: 19485446 DOI: 10.1063/1.3139522] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Elastic tensor and depolarization cross sections are computed for the collision of two exemplary diatomic molecules with (2)Pi electronic ground states-OH and NO-with argon. The interaction of a diatomic molecule in a Pi state with a spherical collision partner must be described by two potential energy surfaces (PESs), corresponding to the two asymptotically degenerate electronic states, of A(') and A(") symmetry. Quantum scattering calculations are most naturally based on the average (V(sum)) and half-difference (V(dif)) of these two PESs. When V(dif) is neglected, the OH(X (2)Pi)-Ar depolarization cross sections are found to be significantly reduced in magnitude, while the NO(X (2)Pi)-Ar cross sections are relatively unaffected. In addition, treating the molecules as closed-shell (1)Sigma(+) species with a corresponding rotational level structure and using (V(sum)) to model the PES, we predict depolarization cross sections which differ significantly from those based on full inclusion of the electronic degeneracy and fine structure of these (2)Pi molecules. This indicates that any single-PES-based simulation of the collisional depolarization of these two molecules would be subject to significant error.
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Affiliation(s)
- Paul J Dagdigian
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218-2685, USA.
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Dagdigian PJ, Alexander MH. Tensor cross sections and collisional depolarization of OH(X 2Π) in collisions with helium. J Chem Phys 2009; 130:164315. [DOI: 10.1063/1.3119978] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Dagdigian PJ, Alexander MH. Tensor cross sections and the collisional evolution of state multipoles: OH(XΠ2)–Ar. J Chem Phys 2009; 130:094303. [DOI: 10.1063/1.3078386] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Brouard M, Bryant A, Chang YP, Cireasa R, Eyles CJ, Green AM, Marinakis S, Aoiz FJ, Kłos J. Collisional depolarization of OH(A) with Ar: Experiment and theory. J Chem Phys 2009; 130:044306. [DOI: 10.1063/1.3061551] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Paterson G, Marinakis S, Kłos J, Costen ML, McKendrick KG. Depolarisation of rotational orientation and alignment in OH (X2Π) + Xe collisions. Phys Chem Chem Phys 2009; 11:8804-12. [DOI: 10.1039/b909050a] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Paterson G, Marinakis S, Costen ML, McKendrick KG. Depolarisation of rotational orientation and alignment of OH (X2Π) in collisions with molecular partners: N2 and O2. Phys Chem Chem Phys 2009; 11:8813-20. [DOI: 10.1039/b909051g] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Brouard M, Chadwick H, Chang YP, Cireasa R, Eyles CJ, La Via AO, Screen N, Aoiz FJ, Kłos J. Collisional depolarization of NO(A) by He and Ar studied by quantum beat spectroscopy. J Chem Phys 2009. [DOI: 10.1063/1.3212608] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Bartlett NCM, Miller DJ, Zare RN, Alexander AJ, Sofikitis D, Rakitzis TP. Time-dependent depolarization of aligned HD molecules. Phys Chem Chem Phys 2009; 11:142-7. [DOI: 10.1039/b814133a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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