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Wang R, Sun Z, Alexander MH. Development of the Time-Independent Methods for the Cl + H 2/F + HD Reaction Using Hyper-Spherical Coordinates Including (Full) Spin-Orbit Characteristics. J Chem Theory Comput 2024; 20:3449-3461. [PMID: 38691764 DOI: 10.1021/acs.jctc.4c00161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2024]
Abstract
Recently, a combined study of high-resolution molecular crossed beam experiment and accurate full-dimensional time-dependent theory, including full spin-orbit characteristics on the effect of electronic spin and orbital angular momenta in the F + HD reaction, was reported by some of us, focusing on the partial wave resonance phenomenon (Science 2021, 371, 936-940). It revealed that the time-dependent theory could explain all of the details observed in the high-resolution experiment. Here, we develop two time-independent close-coupling methods using hyperspherical coordinates, including the two-state model, where only a part of the spin-orbit characteristics is considered, and the six-state model, where the full spin-orbit characteristics is considered. With these two newly developed theoretical models and the adiabatic theoretical model, the detailed reaction dynamics of the F + HD (v = 0, j = 0) reaction and the Cl + H2 (v = 0, j = 0) reaction are investigated and compared. Some of the results are compared with the time-dependent quantum wave packet theory and the experimental observations, and good agreements have been obtained, which suggests the validity of the pure-procession approximation in the six-state model using different theoretical methods. This work demonstrates the ability of the reactive scattering theory including full spin-orbit characteristics for describing the reactions of a halogen atom plus hydrogen molecule and its isotopologues.
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Affiliation(s)
- Ransheng Wang
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhigang Sun
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Millard H Alexander
- Department of Chemistry and Biochemistry and Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, United States
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2
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Kendrick BK. Quantum reactive scattering calculations for the cold and ultracold Li + LiNa → Li 2 + Na reaction. J Chem Phys 2021; 154:124303. [PMID: 33810695 DOI: 10.1063/5.0045712] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A first-principles based quantum dynamics study of the Li + LiNa(v = 0, j = 0) → Li2(v', j') + Na reaction is reported for collision energies spanning the ultracold (1 nK) to cold (1 K) regimes. A full-dimensional ab initio potential energy surface for the ground electronic state of Li2Na is utilized that includes an accurate treatment of the long-range interactions. The Li + LiNa reaction is barrierless and exoergic and exhibits a deep attractive potential well that supports complex formation. Thus, significant reactivity occurs even for collision temperatures approaching absolute zero. The reactive scattering calculations are based on a numerically exact time-independent quantum dynamics methodology in hyperspherical coordinates. Total and rotationally resolved rate coefficients are reported at 56 collision energies and include all contributing partial waves. Several shape resonances are observed in many of the rotationally resolved rate coefficients and a small resonance feature is also reported in the total rate coefficient near 50 mK. Of particular interest, the angular distributions or differential cross sections are reported as a function of both the collision energy and scattering angle. Unique quantum fingerprints (bumps, channels, and ripples) are observed in the angular distributions for each product rotational state due to quantum interference and shape resonance contributions. The Li + LiNa reaction is under active experimental investigation so that these intriguing features could be verified experimentally when sufficient product state resolution becomes feasible for collision energies below 1 K.
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Affiliation(s)
- Brian K Kendrick
- Theoretical Division (T-1, MS B221), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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3
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De Fazio D, Aquilanti V, Cavalli S. Benchmark Quantum Kinetics at Low Temperatures toward Absolute Zero and Role of Entrance Channel Wells on Tunneling, Virtual States, and Resonances: The F + HD Reaction. J Phys Chem A 2020; 124:12-20. [PMID: 31829589 DOI: 10.1021/acs.jpca.9b08435] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This paper reports a study of the quantum reaction dynamics and kinetics of the F + HD reaction at low and ultralow temperatures, focusing on the range from the Wigner limit up to 50 K. Close coupling time-independent quantum reactive scattering calculations for the production of HF and DF molecules have been carried out on two potential energy surfaces differing in the description of the reaction entrance channel. This case is computationally more demanding than the cases of F with H2 and D2 ( De Fazio et al. Frontiers in Chemistry 2019 , 7 , 328 ) but offers a wider phenomenology regarding the roles of quantum mechanical effects of tunneling, of virtual states, and of resonances. The results show that at the temperatures in the cold and ultracold regimes small changes in the entrance channel long-range interaction induce surprising near threshold features. The presence of a virtual state close to the reactive threshold gives rise to a marked anti-Arrhenius behavior of the rate constants below 100 mK. This effect enhances reaction rates by about 2 orders of magnitude, making them of the same order as those at room temperature and confining the onset of the Wigner regime in the microkelvin region.
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Affiliation(s)
- Dario De Fazio
- Istituto di Struttura della materia-Consiglio Nazionale delle Ricerche , 00016 Roma , Italy
| | - Vincenzo Aquilanti
- Istituto di Struttura della materia-Consiglio Nazionale delle Ricerche , 00016 Roma , Italy.,Dipartimento di Chimica, Biologia e Biotecnologie , Università di Perugia , 06123 Perugia , Italy
| | - Simonetta Cavalli
- Dipartimento di Chimica, Biologia e Biotecnologie , Università di Perugia , 06123 Perugia , Italy
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Niman JW, Kamerin BS, Merthe DJ, Kranabetter L, Kresin VV. Oriented Polar Molecules Trapped in Cold Helium Nanodropets: Electrostatic Deflection, Size Separation, and Charge Migration. PHYSICAL REVIEW LETTERS 2019; 123:043203. [PMID: 31491260 DOI: 10.1103/physrevlett.123.043203] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Indexed: 06/10/2023]
Abstract
Helium nanodroplets doped with polar molecules are studied by electrostatic deflection. This broadly applicable method allows even polyatomic molecules to attain subkelvin temperatures and nearly full orientation in the field. The resulting intense force from the field gradient strongly deflects even droplets with tens of thousands of atoms, the most massive neutral systems studied by beam "deflectometry." We use the deflections to extract droplet size distributions. Moreover, since each host droplet deflects according to its mass, spatial filtering of the deflected beam translates into size filtering of neutral fragile nanodroplets. As an example, we measure the dopant ionization probability as a function of droplet radius and determine the mean free path for charge hopping through the helium matrix. The technique will enable separation of doped and neat nanodroplets and size-dependent spectroscopic studies.
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Affiliation(s)
- John W Niman
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089-0484, USA
| | - Benjamin S Kamerin
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089-0484, USA
| | - Daniel J Merthe
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089-0484, USA
| | - Lorenz Kranabetter
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria
| | - Vitaly V Kresin
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089-0484, USA
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5
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Abstract
This article discusses applications of Bayesian machine learning for quantum molecular dynamics.
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Affiliation(s)
- R. V. Krems
- Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
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6
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McDonald M, Majewska I, Lee CH, Kondov SS, McGuyer BH, Moszynski R, Zelevinsky T. Control of Ultracold Photodissociation with Magnetic Fields. PHYSICAL REVIEW LETTERS 2018; 120:033201. [PMID: 29400515 DOI: 10.1103/physrevlett.120.033201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Indexed: 06/07/2023]
Abstract
Photodissociation of a molecule produces a spatial distribution of photofragments determined by the molecular structure and the characteristics of the dissociating light. Performing this basic reaction at ultracold temperatures allows its quantum mechanical features to dominate. In this regime, weak applied fields can be used to control the reaction. Here, we photodissociate ultracold diatomic strontium in magnetic fields below 10 G and observe striking changes in photofragment angular distributions. The observations are in excellent agreement with a multichannel quantum chemistry model that includes nonadiabatic effects and predicts strong mixing of partial waves in the photofragment energy continuum. The experiment is enabled by precise quantum-state control of the molecules.
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Affiliation(s)
- M McDonald
- Department of Physics, Columbia University, 538 West 120th Street, New York, New York 10027-5255, USA
| | - I Majewska
- Quantum Chemistry Laboratory, Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| | - C-H Lee
- Department of Physics, Columbia University, 538 West 120th Street, New York, New York 10027-5255, USA
| | - S S Kondov
- Department of Physics, Columbia University, 538 West 120th Street, New York, New York 10027-5255, USA
| | - B H McGuyer
- Department of Physics, Columbia University, 538 West 120th Street, New York, New York 10027-5255, USA
| | - R Moszynski
- Quantum Chemistry Laboratory, Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| | - T Zelevinsky
- Department of Physics, Columbia University, 538 West 120th Street, New York, New York 10027-5255, USA
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7
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Pawlak M, Shagam Y, Klein A, Narevicius E, Moiseyev N. Adiabatic Variational Theory for Cold Atom–Molecule Collisions: Application to a Metastable Helium Atom Colliding with ortho- and para-Hydrogen Molecules. J Phys Chem A 2017; 121:2194-2198. [PMID: 28221791 DOI: 10.1021/acs.jpca.6b13038] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mariusz Pawlak
- Faculty
of Chemistry, Nicolaus Copernicus University in Toruń, Gagarina
7, 87-100 Toruń, Poland
| | - Yuval Shagam
- Department
of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Ayelet Klein
- Department
of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Edvardas Narevicius
- Department
of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Nimrod Moiseyev
- Schulich
Faculty of Chemistry and Faculty of Physics, Technion−Israel Institute of Technology, Haifa 32000, Israel
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8
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Vieira D, Krems RV, Tscherbul TV. Molecular collisions and reactive scattering in external fields: Are field-induced couplings important at short range? J Chem Phys 2017; 146:024102. [PMID: 28088162 DOI: 10.1063/1.4973431] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We use accurate quantum scattering calculations to elucidate the role of short-range molecule-field interactions in atom-molecule inelastic collisions and abstraction chemical reactions at low temperatures. We consider two examples: elastic and inelastic scattering of NH(Σ3) molecules with Mg(S1) atoms in a magnetic field; reactive scattering LiF + H → Li + HF in an electric field. Our calculations suggest that, for non-reactive collision systems and abstraction chemical reactions, the molecule-field interactions cannot generally be neglected at short range because the atom-molecule potential passes through zero at short range. An important exception occurs for Zeeman transitions in atom-molecule collisions at magnetic fields ≲1000 G, for which the molecule-field couplings need only be included at large ρ outside the range of the atom-molecule interaction. Our results highlight the importance of an accurate description of ρ-dependent molecule-field interactions in quantum scattering calculations on molecular collisions and chemical reactions at low temperatures.
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Affiliation(s)
- D Vieira
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - R V Krems
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - T V Tscherbul
- Department of Physics, University of Nevada, Reno, Nevada 89557, USA
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9
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Balakrishnan N. Perspective: Ultracold molecules and the dawn of cold controlled chemistry. J Chem Phys 2016; 145:150901. [DOI: 10.1063/1.4964096] [Citation(s) in RCA: 157] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- N. Balakrishnan
- Department of Chemistry, University of Nevada, Las Vegas, Nevada 89154, USA
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10
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Pawlak M, Shagam Y, Narevicius E, Moiseyev N. Adiabatic theory for anisotropic cold molecule collisions. J Chem Phys 2015; 143:074114. [PMID: 26298122 DOI: 10.1063/1.4928690] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Mariusz Pawlak
- Schulich Faculty of Chemistry, Technion–Israel Institute of Technology, Haifa 32000, Israel
- Faculty of Chemistry, Nicolaus Copernicus University in Toruń, Gagarina 7, 87-100 Toruń, Poland
| | - Yuval Shagam
- Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Edvardas Narevicius
- Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Nimrod Moiseyev
- Schulich Faculty of Chemistry, Technion–Israel Institute of Technology, Haifa 32000, Israel
- Faculty of Physics, Technion–Israel Institute of Technology, Haifa 32000, Israel
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11
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Englert BGU, Mielenz M, Sommer C, Bayerl J, Motsch M, Pinkse PWH, Rempe G, Zeppenfeld M. Storage and adiabatic cooling of polar molecules in a microstructured trap. PHYSICAL REVIEW LETTERS 2011; 107:263003. [PMID: 22243155 DOI: 10.1103/physrevlett.107.263003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Revised: 09/23/2011] [Indexed: 05/31/2023]
Abstract
We present a versatile electric trap for the exploration of a wide range of quantum phenomena in the interaction between polar molecules. The trap combines tunable fields, homogeneous over most of the trap volume, with steep gradient fields at the trap boundary. An initial sample of up to 10(8), CH(3)F molecules is trapped for as long as 60 s, with a 1/e storage time of 12 s. Adiabatic cooling down to 120 mK is achieved by slowly expanding the trap volume. The trap combines all ingredients for opto-electrical cooling, which, together with the extraordinarily long storage times, brings field-controlled quantum-mechanical collision and reaction experiments within reach.
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Affiliation(s)
- B G U Englert
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Str. 1, D-85748 Garching, Germany
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12
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Li X, Brue DA, Kendrick BK, Blandon JD, Parker GA. Geometric phase for collinear conical intersections. I. Geometric phase angle and vector potentials. J Chem Phys 2011; 134:064108. [PMID: 21322662 DOI: 10.1063/1.3549725] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a method for properly treating collinear conical intersections in triatomic systems. The general vector potential (gauge theory) approach for including the geometric phase effects associated with collinear conical intersections in hyperspherical coordinates is presented. The current study develops an introductory method in the treatment of collinear conical intersections by using the phase angle method. The geometric phase angle, η, in terms of purely internal coordinates is derived using the example of a spin-aligned quartet lithium triatomic system. A numerical fit and thus an analytical form for the associated vector potentials are explicitly derived for this triatomic A(3) system. The application of this methodology to AB(2) and ABC systems is also discussed.
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Affiliation(s)
- Xuan Li
- Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, Oklahoma 73019, USA.
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13
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Balakrishnan N, Quéméner G, Forrey RC, Hinde RJ, Stancil PC. Full-dimensional quantum dynamics calculations of H2–H2 collisions. J Chem Phys 2011; 134:014301. [PMID: 21218997 DOI: 10.1063/1.3511699] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- N Balakrishnan
- Department of Chemistry, University of Nevada Las Vegas, Las Vegas, Nevada 89154, USA.
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14
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Lara M, Dayou F, Launay JM. Reaching the cold regime: S(1D) + H2 and the role of long-range interactions in open shell reactive collisions. Phys Chem Chem Phys 2011; 13:8359-70. [DOI: 10.1039/c0cp02091e] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Tscherbul TV, Dalgarno A. Quantum theory of molecular collisions in a magnetic field: Efficient calculations based on the total angular momentum representation. J Chem Phys 2010; 133:184104. [DOI: 10.1063/1.3503500] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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