Quantum scattering studies of inelastic collisions of NH(A 3Π) with helium: Fine‐structure and Λ‐doublet propensities

1991 ◽  
Vol 95 (7) ◽  
pp. 5036-5046 ◽  
Author(s):  
Millard H. Alexander ◽  
Paul J. Dagdigian ◽  
Didier Lemoine
Keyword(s):  
Fine Structure ◽  
Inelastic Collisions ◽  
Quantum Scattering

Fine-structure state resolved rotationally inelastic collisions of CH(A [sup 2]Δ,v=0) with Ar: A combined experimental and theoretical study

2001 ◽  
Vol 114 (10) ◽  
pp. 4479 ◽  
Author(s):  
M. Kind ◽  
F. Stuhl ◽  
Yi-Ren Tzeng ◽  
Millard H. Alexander ◽  
Paul J. Dagdigian
Keyword(s):  
Fine Structure ◽  
Theoretical Study ◽  
Inelastic Collisions ◽  
Structure State

scholarly journals Breakdown of energy transfer gap laws revealed by full-dimensional quantum scattering between HF molecules

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Dongzheng Yang ◽  
Jing Huang ◽  
Xixi Hu ◽  
Hua Guo ◽  
Daiqian Xie
Keyword(s):  
Energy Transfer ◽  
Angular Momentum ◽  
Vibrational Energy ◽  
Energy Gap ◽  
Inelastic Collisions ◽  
Rate Coefficients ◽  
Quantum Scattering ◽  
Final States ◽  
Energy Gap Law ◽  
Quantitative Basis

Abstract Inelastic collisions involving molecular species are key to energy transfer in gaseous environments. They are commonly governed by an energy gap law, which dictates that transitions are dominated by those between initial and final states with roughly the same ro-vibrational energy. Transitions involving rotational inelasticity are often further constrained by the rotational angular momentum. Here, we demonstrate using full-dimensional quantum scattering on an ab initio based global potential energy surface (PES) that HF–HF inelastic collisions do not obey the energy and angular momentum gap laws. Detailed analyses attribute the failure of gap laws to the exceedingly strong intermolecular interaction. On the other hand, vibrational state-resolved rate coefficients are in good agreement with existing experimental results, validating the accuracy of the PES. These new and surprising results are expected to extend our understanding of energy transfer and provide a quantitative basis for numerical simulations of hydrogen fluoride chemical lasers.

Rate coefficients for rotationally inelastic collisions of CO with H2

2001 ◽  
Vol 79 (2-3) ◽  
pp. 589-595 ◽  
Author(s):  
M Mengel ◽  
F C De Lucia ◽  
E Herbst
Keyword(s):  
Potential Energy ◽  
Energy Surface ◽  
Potential Surface ◽  
Chem Phys ◽  
Inelastic Collisions ◽  
Rate Coefficients ◽  
Quantum Scattering ◽  
Collision System ◽  
Pressure Broadening ◽  
Experimental Pressure

We have performed quantum-scattering calculations to determine inelastic rate coefficients of the astrophysically important collision system CO–H2. We have used a modified version of the most recent potential-energy surface by Jankowski and Szalewicz (J. Chem. Phys. 108, 3554 (1998)), which has been proven to be superior to a previous potential surface by comparison with experimental pressure broadening data. In contrast to previous studies we find that inelastic rates with Δ J = 2 for CO are smaller than those with Δ J = 1. PACS No.: 34.50Ez

Inelastic collisions of fine structure and Λ-doublet resolved rotational states of PH(A 3Π, v=0) with helium

1997 ◽  
Vol 106 (18) ◽  
pp. 7642-7653 ◽  
Author(s):  
L. Neitsch ◽  
F. Stuhl ◽  
Paul J. Dagdigian ◽  
Millard H. Alexander
Keyword(s):  
Fine Structure ◽  
Inelastic Collisions ◽  
Rotational States

Inelastic Collisions between Excited Alkali Atoms and Molecules. VIII. 62P1/2–62P3/2 Mixing and Quenching in Mixtures of Rubidium with H2, HD, D2, N2, CH4, and CD4

1973 ◽  
Vol 51 (3) ◽  
pp. 257-265 ◽  
Author(s):  
I. N. Siara ◽  
L. Krause
Keyword(s):  
Fine Structure ◽  
Cross Sections ◽  
Ground State ◽  
Inelastic Collisions ◽  
Fluorescent Intensity ◽  
Rubidium Vapor ◽  
Sensitized Fluorescence ◽  
Molecular Gases ◽  
Alkali Atoms ◽  
Intensity Ratios

Excitation transfer between the 62P fine-structure substates in rubidium, induced in inelastic collisions with ground-state molecules, has been studied using techniques of sensitized fluorescence. Rubidium vapor in mixtures with various molecular gases was irradiated with each component of the 2P rubidium doublet in turn, and measurements of sensitized-to-resonance fluorescent intensity ratios yielded the following mixing cross sections Q12(2P1/2 → 2P3/2) and Q21(2P1/2 ← 2P3/2), as well as effective quenching cross sections Q1X(2P1/2 → 2XJ″) and Q2X(2P3/2 → 2XJ″). For collisions with H2: Q12(2P1/2 → 2P3/2) = (41 ± 5) Å2; Q21(2P1/2 ← 2P3/2) = (26 ± 3) Å2; Q1X(2P1/2 → 2XJ″) = (36 ± 9) Å2; Q2X(2P3/2 → 2XJ″) = (31 ± 8) Å2. For HD: Q12 = (42 ± 5) Å2; Q21 = (27 ± 4) Å2; Q1X = (47 ± 13) Å2; Q2X = (38 ± 10) Å2. For D2: Q12 = (42 ± 5) Å2; Q21 = (27 ± 4) Å2; Q1X = (28 ± 8) Å2; Q2X = (21 ± 7) Å2. For N2: Q12 = (107 ± 15) Å2; Q21 = (70 ± 10) Å2; Q1X = (128 ± 44) Å2; Q2X = (126 ± 33) Å2. For CH4: Q12 = (38 ± 6) Å2; Q21 = (24 ± 3) Å2; Q1X = (129 ± 41) Å2; Q2X = (114 ± 37) Å2. For CD4: Q12 = (52 ± 7) Å2; Q21 = (34 ± 5) Å2; Q1X = (82 ± 30) Å2; Q2X = (76 ± 22) Å2. An analysis of these results suggests the possibility of resonances with various molecular rotational and vibrational transitions.

The Fine Structure of Alkali Metal Atoms in Inelastic Collisions with Hydrogen

2019 ◽  
Vol 127 (2) ◽  
pp. 207-211 ◽  
Author(s):  
S. A. Yakovleva ◽  
Ya. V. Voronov ◽  
A. K. Belyaev
Keyword(s):  
Fine Structure ◽  
Alkali Metal ◽  
Inelastic Collisions ◽  
Metal Atoms

Observation of Partial Wave Resonances in Low-Energy O2–H2 Inelastic Collisions

Science ◽  
2013 ◽  
Vol 341 (6150) ◽  
pp. 1094-1096 ◽  
Author(s):  
Simon Chefdeville ◽  
Yulia Kalugina ◽  
Sebastiaan Y. T. van de Meerakker ◽  
Christian Naulin ◽  
François Lique ◽  
...  
Keyword(s):  
Partial Wave ◽  
Cross Sections ◽  
Ground State ◽  
Total Angular Momentum ◽  
Inelastic Collisions ◽  
Quantum Mechanical ◽  
Quantum Scattering ◽  
Rotational Excitation ◽  
Collision Processes ◽  
Theoretical Results

Partial wave resonances predicted to occur in bimolecular collision processes have proven challenging to observe experimentally. Here, we report crossed-beam experiments and quantum-scattering calculations on inelastic collisions between ground-state O2 and H2 molecules that provide state-to-state cross sections for rotational excitation of O2 (rotational state N = 1, j = 0) to O2 (N = 1, j = 1) in the vicinity of the thermodynamic threshold at 3.96 centimeter−1. The close agreement between experimental and theoretical results confirms the classically forbidden character of this collision-induced transition, which occurs exclusively in a purely quantum mechanical regime via shape and Feshbach resonances arising from partial waves with total angular momentum (J) = 2 to 4.

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