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Guan Y, Chen Q, Varandas AJC. Accurate diabatization based on combined-hyperbolic-inverse-power-representation: 1,2 2A' states of BeH2. J Chem Phys 2024; 160:154105. [PMID: 38624109 DOI: 10.1063/5.0200732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Accepted: 03/28/2024] [Indexed: 04/17/2024] Open
Abstract
A diabatic potential energy matrix (DPEM) for the two lowest states of BeH2+ has been constructed using the combined-hyperbolic-inverse-power-representation (CHIPR) method. By imposing symmetry constraints on the coefficients of polynomials, the complete nuclear permutation inversion symmetry is correctly preserved in the CHIPR functional form. The symmetrized CHIPR functional form is then used in the diabatization by ansatz procedure. The ab initio energies are reproduced with satisfactory accuracy. In addition, the CHIPR-based DPEM also reproduces the local topology of a conical intersection. Future work will focus on a complete four-state diabatic representation with emphasis on the long-range interactions and spin-orbit couplings, which will enable accurate quantum scattering calculations for the Be+(2P) + H2 → BeH+(X1Σ+) + H(2S) reaction.
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Affiliation(s)
- Yafu Guan
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
| | - Qun Chen
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
| | - António J C Varandas
- School of Physics and Physical Engineering, Qufu Normal University, 273165 Qufu, People's Republic of China
- Department of Physics, Universidade Federal do Espírito Santo, 29075-910 Vitória, Brazil
- Department of Chemistry and Chemistry Centre, University of Coimbra, 3004-535 Coimbra, Portugal
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2
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Song Z, Han J, Henkelman G, Li L. Charge-Optimized Electrostatic Interaction Atom-Centered Neural Network Algorithm. J Chem Theory Comput 2024; 20:2088-2097. [PMID: 38380601 DOI: 10.1021/acs.jctc.3c01254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Machine-learning algorithms have been proposed to capture electrostatic interactions by using effective partial charges. These algorithms often rely on a pretrained model for partial charge prediction using density functional theory-calculated partial charges as references, which introduces complexity to the force field model. The accuracy of the trained model also depends on the reliability of charge partition methods, which can be dependent on the specific system and methodology employed. In this study, we propose an atom-centered neural network (ANN) algorithm that eliminates the need for reference charges. Our algorithm requires only a single NN model for each element to obtain both atomic energy and charges. These atomic charges are then employed to compute electrostatic energies using the Ewald summation algorithm. Subsequently, the force field model is trained on total energy and forces, with the inclusion of electrostatic energy. To evaluate the performance of our algorithm, we conducted tests on three benchmark systems, including a Ge slab with an O adatom system, a TiO2 crystalline system, and a Pd-O nanoparticle system. Our results demonstrate reasonably accurate predictions of partial charges and electrostatic interactions. This algorithm provides a self-consistent charge prediction strategy and possibilities for robust and reliable modeling of electrostatic interactions in machine-learning potentials.
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Affiliation(s)
- Zichen Song
- Shenzhen Key Laboratory of Micro/Nano-Porous Functional Materials (SKLPM), Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- Department of Materials Science and Engineering, City University of Hong Kong, Kowloon, Hong Kong, China
| | - Jian Han
- Department of Materials Science and Engineering, City University of Hong Kong, Kowloon, Hong Kong, China
| | - Graeme Henkelman
- Department of Chemistry, the University of Texas at Austin, Austin, Texas 78712, United States
- Institute for Computational Engineering and Sciences, the University of Texas at Austin, Austin, Texas 78712, United States
| | - Lei Li
- Shenzhen Key Laboratory of Micro/Nano-Porous Functional Materials (SKLPM), Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
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Morita M, Kendrick BK, Kłos J, Kotochigova S, Brumer P, Tscherbul TV. Signatures of Non-universal Quantum Dynamics of Ultracold Chemical Reactions of Polar Alkali Dimer Molecules with Alkali Metal Atoms: Li( 2S) + NaLi( a3Σ +) → Na( 2S) + Li 2( a3Σ u+). J Phys Chem Lett 2023; 14:3413-3421. [PMID: 37001115 DOI: 10.1021/acs.jpclett.3c00159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Ultracold chemical reactions of weakly bound triplet-state alkali metal dimer molecules have recently attracted much experimental interest. We perform rigorous quantum scattering calculations with a new ab initio potential energy surface to explore the chemical reaction of spin-polarized NaLi(a3Σ+) and Li(2S) to form Li2(a3Σu+) and Na(2S). The reaction is exothermic and proceeds readily at ultralow temperatures. Significantly, we observe strong sensitivity of the total reaction rate to small variations of the three-body part of the Li2Na interaction at short range, which we attribute to a relatively small number of open Li2(a3Σu+) product channels populated in the reaction. This provides the first signature of highly non-universal dynamics seen in rigorous quantum reactive scattering calculations of an ultracold exothermic insertion reaction involving a polar alkali dimer molecule, opening up the possibility of probing microscopic interactions in atom+molecule collision complexes via ultracold reactive scattering experiments.
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Affiliation(s)
- Masato Morita
- Chemical Physics Theory Group, Department of Chemistry, and Center for Quantum Information and Quantum Control, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Brian K Kendrick
- Theoretical Division (T-1, MS B221), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Jacek Kłos
- Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, United States
- Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, United States
| | - Svetlana Kotochigova
- Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, United States
| | - Paul Brumer
- Chemical Physics Theory Group, Department of Chemistry, and Center for Quantum Information and Quantum Control, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Timur V Tscherbul
- Department of Physics, University of Nevada, Reno, Nevada 89557, United States
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4
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Mukherjee N. Quantum-Controlled Collisions of H 2 Molecules. J Phys Chem A 2023; 127:418-438. [PMID: 36602238 DOI: 10.1021/acs.jpca.2c06808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The amount of information that can be obtained from a scattering experiment depends upon the precision with which the quantum states are defined in the incoming channel. By precisely defining the incoming states and measuring the outgoing states in a scattering experiment, we set up the boundary condition for experimentally solving the Schrödinger equation. In this Perspective we discuss cold inelastic scattering experiments using the most theoretically tractable H2 and its isotopologues as the target. We prepare the target in a precisely defined rovibrational (v, j, m) quantum state using a special coherent optical technique called the Stark-induced adiabatic Raman passage (SARP). v and j represent the quantum numbers of the vibrational and rotational energy levels, and m refers to the projection of the rotational angular momentum vector j on a suitable quantization axis in the laboratory frame. Selection of the m quantum numbers defines the alignment of the molecular frame, which is necessary to probe the anisotropic interactions. For us to achieve the collision temperature in the range of a few degrees Kelvin, we co-expand the colliding partners in a mixed supersonic beam that is collimated to define a direction for the collision velocity. When the bond axis is aligned with respect to a well-defined collision velocity, SARP achieves stereodynamic control at the quantum scale. Through various examples of rotationally inelastic cold scattering experiments, we show how SARP coherently controls the dynamics of anisotropic interactions by preparing quantum superpositions of the orientational m states within a single rovibrational (v, j) energy state. A partial wave analysis, which has been developed for the cold scattering experiments, shows dominance of a resonant orbital that leaves its mark in the scattering angular distribution. These highly controlled cold collision experiments at the single partial wave limit allow the most direct comparison with the results of theoretical computations, necessary for accurate modeling of the molecular interaction potential.
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Affiliation(s)
- Nandini Mukherjee
- Department of Chemistry, Stanford University, Stanford, California94305, United States
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5
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Zhou H, Perreault WE, Mukherjee N, Zare RN. Anisotropic dynamics of resonant scattering between a pair of cold aligned diatoms. Nat Chem 2022; 14:658-663. [PMID: 35501483 DOI: 10.1038/s41557-022-00926-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 03/09/2022] [Indexed: 11/09/2022]
Abstract
The collision dynamics between a pair of aligned molecules in the presence of a partial-wave resonance provide the most sensitive probe of the long-range anisotropic forces important to chemical reactions. Here we control the collision temperature and geometry to probe the dynamics of cold (1-3 K) rotationally inelastic scattering of a pair of optically state-prepared D2 molecules. The collision temperature is manipulated by combining the gating action of laser state preparation and detection with the velocity dispersion of the molecular beam. When the bond axes of both molecules are aligned parallel to the collision velocity, the scattering rate drops by a factor of 3.5 as collision energies >2.1 K are removed, suggesting a geometry-dependent resonance. Partial-wave analysis of the measured angular distribution supports a shape resonance within the centrifugal barrier of the l = 2 incoming orbital. Our experiment illustrates the strong anisotropy of the quadrupole-quadrupole interaction that controls the dynamics of resonant scattering.
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Affiliation(s)
- Haowen Zhou
- Department of Chemistry, Stanford University, Stanford, CA, USA
| | | | | | - Richard N Zare
- Department of Chemistry, Stanford University, Stanford, CA, USA.
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6
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Yang D, Xie D, Guo H. Stereodynamical Control of Cold Collisions of Polyatomic Molecules with Atoms. J Phys Chem Lett 2022; 13:1777-1784. [PMID: 35167302 DOI: 10.1021/acs.jpclett.2c00187] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Scattering between atomic and/or molecular species can be controlled by manipulating the orientation or alignment of the collision partners. Such stereodynamics is particularly pronounced at cold (∼1 K) collision temperatures because of the presence of resonances. Comparing to the extensively studied atomic and diatomic species, polyatomic molecules with strong steric anisotropy could provide a more sophisticated platform for studying such stereodynamics. Here, we provide the quantum mechanical framework for understanding state-to-state stereodynamics in rotationally inelastic scattering of polyatomic molecules with atoms and apply it to cold collision of oriented H2O with He on a highly accurate potential energy surface. It is shown that strong stereodynamical control can be achieved near 1 K via shape resonances. Furthermore, quantum interference in scattering of a coherently prepared initial state of the H2O species is explored, which is shown to be significant.
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Affiliation(s)
- Dongzheng Yang
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Daiqian Xie
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Hua Guo
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, United States
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7
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Abstract
Advances in atomic, molecular, and optical physics techniques allowed the cooling of simple molecules down to the ultracold regime ([Formula: see text]1 mK) and opened opportunities to study chemical reactions with unprecedented levels of control. This review covers recent developments in studying bimolecular chemistry at ultralow temperatures. We begin with a brief overview of methods for producing, manipulating, and detecting ultracold molecules. We then survey experimental works that exploit the controllability of ultracold molecules to probe and modify their long-range interactions. Further combining the use of physical chemistry techniques such as mass spectrometry and ion imaging significantly improved the detection of ultracold reactions and enabled explorations of their dynamics in the short range. We discuss a series of studies on the reaction KRb + KRb → K2 + Rb2 initiated below 1 [Formula: see text]K, including the direct observation of a long-lived complex, the demonstration of product rotational state control via conserved nuclear spins, and a test of the statistical model using the complete quantum state distribution of the products. Expected final online publication date for the Annual Review of Physical Chemistry, Volume 73 is April 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Yu Liu
- Time and Frequency Division, National Institute of Standards and Technology, Boulder, Colorado 80305, USA; .,Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Kang-Kuen Ni
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA; .,Harvard-Massachusetts Institute of Technology Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
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8
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da Silva RS, Ballester MY. A theoretical investigation of the $${{\rm SO}}({{B}^{3}\Sigma ^{-}{-}{X}^{3}\Sigma ^{-}}$$) vibronic transition using accurate analytical potential energy functions. Theor Chem Acc 2020. [DOI: 10.1007/s00214-020-2571-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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9
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Toscano J, Lewandowski HJ, Heazlewood BR. Cold and controlled chemical reaction dynamics. Phys Chem Chem Phys 2020; 22:9180-9194. [DOI: 10.1039/d0cp00931h] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
State-to-state chemical reaction dynamics, with complete control over the reaction parameters, offers unparalleled insight into fundamental reactivity.
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Affiliation(s)
- Jutta Toscano
- JILA and the Department of Physics
- University of Colorado
- Boulder
- USA
| | | | - Brianna R. Heazlewood
- Physical and Theoretical Chemistry Laboratory (PTCL)
- Department of Chemistry
- University of Oxford
- Oxford
- UK
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10
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Guerrero RD, Castellanos MA, Arango CA. Heuristic optimization of analytic laser pulses for vibrational stabilization of ultracold KRb. J Chem Phys 2018; 149:244110. [PMID: 30599711 DOI: 10.1063/1.5052019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
We proposed a methodology that allows to maximize the population transfer from a high vibrational state of the a 3Σ+ triplet state to the vibrational ground state of the X 1Σ+ singlet state though the optimization of one pump and one dump laser pulses. The pump pulse is optimized using a fitness function, heuristically improved, that includes the effect of the spin-orbit coupling of the KRb [b-A]-scheme. The dump pulse is optimized to maximize the population transfer to the ground state. We performed a comparison with the case in which the pump and dump pulses are optimized to maximize the population transfer to the ground state employing a genetic algorithm with a single fitness function. The heuristic approach turned out to be 70% more efficient than a quantum optimal control optimization employing a single fitness function. The method proposed provides simple pulses that have an experimental realm.
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Affiliation(s)
- Rubén D Guerrero
- PULSE Institute and Department of Chemistry, Stanford University, Stanford, California 94305, USA
| | | | - Carlos A Arango
- Department of Chemical Sciences, Universidad Icesi, Cali, Colombia
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11
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Zuo JX, Hu XX, Xie DQ. Quantum Dynamics of Oxyhydrogen Complex-Forming Reactions for the HO2 and HO3 Systems. CHINESE J CHEM PHYS 2018. [DOI: 10.1063/1674-0068/31/cjcp1804060] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Jun-xiang Zuo
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Xi-xi Hu
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Dai-qian Xie
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
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12
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Cold quantum-controlled rotationally inelastic scattering of HD with H 2 and D 2 reveals collisional partner reorientation. Nat Chem 2018; 10:561-567. [PMID: 29662208 DOI: 10.1038/s41557-018-0028-5] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 02/16/2018] [Indexed: 11/08/2022]
Abstract
Molecular interactions are best probed by scattering experiments. Interpretation of these studies has been limited by lack of control over the quantum states of the incoming collision partners. We report here the rotationally inelastic collisions of quantum-state prepared deuterium hydride (HD) with H2 and D2 using a method that provides an improved control over the input states. HD was coexpanded with its partner in a single supersonic beam, which reduced the collision temperature to 0-5 K, and thereby restricted the involved incoming partial waves to s and p. By preparing HD with its bond axis preferentially aligned parallel and perpendicular to the relative velocity of the colliding partners, we observed that the rotational relaxation of HD depends strongly on the initial bond-axis orientation. We developed a partial-wave analysis that conclusively demonstrates that the scattering mechanism involves the exchange of internal angular momentum between the colliding partners. The striking differences between H2/HD and D2/HD scattering suggest the presence of anisotropically sensitive resonances.
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13
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Perreault WE, Mukherjee N, Zare RN. Quantum control of molecular collisions at 1 kelvin. Science 2017; 358:356-359. [DOI: 10.1126/science.aao3116] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 09/08/2017] [Indexed: 11/02/2022]
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Kendrick BK, Hazra J, Balakrishnan N. Geometric phase effects in the ultracold H + H2reaction. J Chem Phys 2016; 145:164303. [DOI: 10.1063/1.4966037] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- B. K. Kendrick
- Theoretical Division (T-1, MS B221), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Jisha Hazra
- Department of Chemistry, University of Nevada, Las Vegas, Nevada 89154, USA
| | - N. Balakrishnan
- Department of Chemistry, University of Nevada, Las Vegas, Nevada 89154, USA
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15
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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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16
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Kendrick BK, Hazra J, Balakrishnan N. Geometric Phase Appears in the Ultracold Hydrogen Exchange Reaction. PHYSICAL REVIEW LETTERS 2015; 115:153201. [PMID: 26550721 DOI: 10.1103/physrevlett.115.153201] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Indexed: 06/05/2023]
Abstract
Quantum reactive scattering calculations for the hydrogen exchange reaction H+H_{2}(v=4,j=0)→H+H_{2}(v^{'}, j^{'}) and its isotopic analogues are reported for ultracold collision energies. Because of the unique properties associated with ultracold collisions, it is shown that the geometric phase effectively controls the reactivity. The rotationally resolved rate coefficients computed with and without the geometric phase are shown to differ by up to 4 orders of magnitude. The effect is also significant in the vibrationally resolved and total rate coefficients. The dynamical origin of the effect is discussed and the large geometric phase effect reported here might be exploited to control the reactivity through the application of external fields or by the selection of a particular nuclear spin state.
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Affiliation(s)
- B K Kendrick
- Theoretical Division (T-1, MS B221), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Jisha Hazra
- Department of Chemistry, University of Nevada, Las Vegas, Nevada 89154, USA
| | - N Balakrishnan
- Department of Chemistry, University of Nevada, Las Vegas, Nevada 89154, USA
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17
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Teixidor MM, Varandas AJC. Quantum dynamics study on the CHIPR potential energy surface for the hydroperoxyl radical: the reactions O + OH⇋O2 + H. J Chem Phys 2015; 142:014309. [PMID: 25573563 DOI: 10.1063/1.4905292] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Quantum scattering calculations of the O((3)P)+OH((2)Π)⇌O2((3)Σg (-))+H((2)S) reactions are presented using the combined-hyperbolic-inverse-power-representation potential energy surface [A. J. C. Varandas, J. Chem. Phys. 138, 134117 (2013)], which employs a realistic, ab initio-based, description of both the valence and long-range interactions. The calculations have been performed with the ABC time-independent quantum reactive scattering computer program based on hyperspherical coordinates. The reactivity of both arrangements has been investigated, with particular attention paid to the effects of vibrational excitation. By using the J-shifting approximation, rate constants are also reported for both the title reactions.
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Affiliation(s)
- Marc Moix Teixidor
- Departamento de Química and Centro de Química, Universidade de Coimbra, 3004-535 Coimbra, Portugal
| | - António J C Varandas
- Departamento de Química and Centro de Química, Universidade de Coimbra, 3004-535 Coimbra, Portugal
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19
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Wang J, Byrd JN, Simbotin I, Côté R. Tuning ultracold chemical reactions via Rydberg-dressed interactions. PHYSICAL REVIEW LETTERS 2014; 113:025302. [PMID: 25062202 DOI: 10.1103/physrevlett.113.025302] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Indexed: 06/03/2023]
Abstract
We show that ultracold chemical reactions with an activation barrier can be tuned using Rydberg-dressed interactions. Scattering in the ultracold regime is sensitive to long-range interactions, especially when weakly bound (or quasibound) states exist near the collision threshold. We investigate how, by Rydberg dressing a reactant, one enhances its polarizability and modifies the long-range van der Waals collision complex, which can alter chemical reaction rates by shifting the position of near-threshold bound states. We carry out a full quantum mechanical scattering calculation for the benchmark system H(2)+D, and show that resonances can be moved substantially and that rate coefficients at cold and ultracold temperatures can be increased by several orders of magnitude.
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Affiliation(s)
- Jia Wang
- Department of Physics, University of Connecticut, 2152 Hillside Road, Storrs, Connecticut 06269, USA
| | - Jason N Byrd
- Department of Physics, University of Connecticut, 2152 Hillside Road, Storrs, Connecticut 06269, USA and Quantum Theory Project, University of Florida, Gainesville, Florida 32611, USA
| | - Ion Simbotin
- Department of Physics, University of Connecticut, 2152 Hillside Road, Storrs, Connecticut 06269, USA
| | - R Côté
- Department of Physics, University of Connecticut, 2152 Hillside Road, Storrs, Connecticut 06269, USA and Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
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González-Lezana T, Honvault P, Scribano Y. Dynamics of the D(+) + H2 → HD + H(+) reaction at the low energy regime by means of a statistical quantum method. J Chem Phys 2014; 139:054301. [PMID: 23927256 DOI: 10.1063/1.4816638] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The D(+) +H2(v = 0, j = 0, 1) → HD+H(+) reaction has been investigated at the low energy regime by means of a statistical quantum mechanical (SQM) method. Reaction probabilities and integral cross sections (ICSs) between a collisional energy of 10(-4) eV and 0.1 eV have been calculated and compared with previously reported results of a time independent quantum mechanical (TIQM) approach. The TIQM results exhibit a dense profile with numerous narrow resonances down to Ec ~ 10(-2) eV and for the case of H2(v = 0, j = 0) a prominent peak is found at ~2.5 × 10(-4) eV. The analysis at the state-to-state level reveals that this feature is originated in those processes which yield the formation of rotationally excited HD(v' = 0, j' > 0). The statistical predictions reproduce reasonably well the overall behaviour of the TIQM ICSs at the larger energy range (Ec ≥ 10(-3) eV). Thermal rate constants are in qualitative agreement for the whole range of temperatures investigated in this work, 10-100 K, although the SQM values remain above the TIQM results for both initial H2 rotational states, j = 0 and 1. The enlargement of the asymptotic region for the statistical approach is crucial for a proper description at low energies. In particular, we find that the SQM method leads to rate coefficients in terms of the energy in perfect agreement with previously reported measurements if the maximum distance at which the calculation is performed increases noticeably with respect to the value employed to reproduce the TIQM results.
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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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Csehi A, Bende A, Halász GJ, Vibók Á, Das A, Mukhopadhyay D, Mukherjee S, Adhikari S, Baer M. Dressed Adiabatic and Diabatic Potentials for the Renner–Teller/Jahn–Teller F + H2 System. J Phys Chem A 2013; 117:8497-505. [DOI: 10.1021/jp311014z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- A. Csehi
- Department of Information
Technology, University of Debrecen, P.O. Box 12, H-4010 Debrecen, Hungary
| | - A. Bende
- Molecular and Biomolecular
Physics Department, National Institute for Research and Development of Isotopic and Molecular Technologies, Cluj-Napoca, Romania
| | - G. J. Halász
- Department of Information
Technology, University of Debrecen, P.O. Box 12, H-4010 Debrecen, Hungary
| | - Á. Vibók
- Department of Theoretical
Physics, University of Debrecen, P.O. Box 5, H-4010 Debrecen, Hungary
| | - A. Das
- Department of Chemistry, University of Calcutta, Kolkata 700
009, India
| | - D. Mukhopadhyay
- Department of Chemistry, University of Calcutta, Kolkata 700
009, India
| | - S. Mukherjee
- Department of Physical
Chemistry, Indian Association for Cultivation of Science, Jadavpur, Kolkata 700 032, India
| | - S. Adhikari
- Department of Physical
Chemistry, Indian Association for Cultivation of Science, Jadavpur, Kolkata 700 032, India
| | - Michael Baer
- Department of Physical
Chemistry, Indian Association for Cultivation of Science, Jadavpur, Kolkata 700 032, India
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24
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Affiliation(s)
- Goulven Quéméner
- JILA, University of Colorado,
Boulder, CO 80309-0440, United States
| | - Paul S. Julienne
- Joint Quantum Institute, NIST
and the University of Maryland, Gaithersburg, Maryland 20899-8423,
United States
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25
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26
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Das A, Sahoo T, Mukhopadhyay D, Adhikari S, Baer M. Dressed adiabatic and diabatic potentials to study conical intersections for F + H2. J Chem Phys 2012; 136:054104. [DOI: 10.1063/1.3679406] [Citation(s) in RCA: 12] [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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27
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Byrd JN, Côté R, Montgomery JA. Long-range interactions between like homonuclear alkali metal diatoms. J Chem Phys 2011; 135:244307. [DOI: 10.1063/1.3671371] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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28
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Das A, Mukhopadhyay D, Adhikari S, Baer M. Derivation of diabatic potentials for F+H2 employing non-adiabatic coupling terms. Chem Phys Lett 2011. [DOI: 10.1016/j.cplett.2011.09.072] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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29
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Lara M, Jambrina PG, Varandas AJC, Launay JM, Aoiz FJ. On the role of dynamical barriers in barrierless reactions at low energies: S(1D) + H2. J Chem Phys 2011; 135:134313. [DOI: 10.1063/1.3644337] [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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30
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Santos SFD, Balakrishnan N, Lepp S, Quéméner G, Forrey RC, Hinde RJ, Stancil PC. Quantum dynamics of rovibrational transitions in H2-H2 collisions: Internal energy and rotational angular momentum conservation effects. J Chem Phys 2011; 134:214303. [DOI: 10.1063/1.3595134] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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31
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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: 33] [Impact Index Per Article: 2.5] [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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32
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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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33
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Juanes-Marcos JC, Quéméner G, Kendrick BK, Balakrishnan N. Ultracold collisions and reactions of vibrationally excited OH radicals with oxygen atoms. Phys Chem Chem Phys 2011; 13:19067-76. [DOI: 10.1039/c1cp21141b] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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34
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Doherty WG, Bell MT, Softley TP, Rowland A, Wrede E, Carty D. Production of cold bromine atoms at zero mean velocity by photodissociation. Phys Chem Chem Phys 2011; 13:8441-7. [DOI: 10.1039/c0cp02472d] [Citation(s) in RCA: 13] [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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35
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Simbotin I, Ghosal S, Côté R. A case study in ultracold reactive scattering: D + H2. Phys Chem Chem Phys 2011; 13:19148-55. [PMID: 21976145 DOI: 10.1039/c1cp21982k] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Ion Simbotin
- University of Connecticut, Department of Physics, 2152 Hillside Road, U-3046, Storrs, CT 06269, USA.
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36
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Berteloite C, Lara M, Bergeat A, Le Picard SD, Dayou F, Hickson KM, Canosa A, Naulin C, Launay JM, Sims IR, Costes M. Kinetics and dynamics of the S(1D2) + H2 → SH + H reaction at very low temperatures and collision energies. PHYSICAL REVIEW LETTERS 2010; 105:203201. [PMID: 21231230 DOI: 10.1103/physrevlett.105.203201] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Indexed: 05/30/2023]
Abstract
We report combined studies on the prototypical S(1D2) + H2 insertion reaction. Kinetics and crossed-beam experiments are performed in experimental conditions approaching the cold energy regime, yielding absolute rate coefficients down to 5.8 K and relative integral cross sections to collision energies as low as 0.68 meV. They are supported by quantum calculations on a potential energy surface treating long-range interactions accurately. All results are consistent and the excitation function behavior is explained in terms of the cumulative contribution of various partial waves.
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Affiliation(s)
- Coralie Berteloite
- Institut de Physique de Rennes, UMR 6251 du CNRS-Université de Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex, France
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37
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Affiliation(s)
- Jeremy M. Hutson
- a Department of Chemistry , University of Durham , South Road, Durham , DH1 3LE , England
| | - Pavel Soldán
- b Faculty of Nuclear Sciences and Physical Engineering , Department of Physics , Doppler Institute , Czech Technical University , Břehová 7 , 115 19 Praha 1 , Czech Republic
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38
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Lipoff SH, Herschbach DR. Low-energy limit for tunnelling subject to an Eckart potential barrier. Mol Phys 2010. [DOI: 10.1080/00268971003662912] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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39
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Bell MT, Gingell AD, Oldham JM, Softley TP, Willitsch S. Ion-molecule chemistry at very low temperatures: cold chemical reactions between Coulomb-crystallized ions and velocity-selected neutral molecules. Faraday Discuss 2010; 142:73-91; discussion 93-111. [PMID: 20151539 DOI: 10.1039/b818733a] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The recent development of a range of techniques for producing cold atoms and molecules at very low translational temperatures T < or = 1 K has provided the opportunity to investigate collisional processes in a new physical regime. We have recently presented a new experimental method to study low-temperature reactive collisions between translationally cold ions and neutral molecules (S. Willitsch et al., Phys. Rev. Lett. 2008, 100, 043203). Our technique relies on the combination of a quadrupole-guide velocity selector for the generation of translationally cold neutral molecules with a facility to produce ordered structures of cold ions (Coulomb crystals) by laser cooling in a linear quadrupole ion trap. The strong localisation of the ions in the trap in combination with the high sensitivity of laser-induced-fluorescence detection enabled us to study chemical reactions on the single-particle level, down to temperatures of T approximately 1 K. In the current paper, we present a detailed characterisation of the scope and limitations of this method based on our study of the reaction between laser-cooled Ca+ ions and velocity-selected CH3F molecules. The properties of our cold-neutrals source and the dependence of the measured rate constant on the shape of the Coulomb crystals, trapping and laser-cooling parameters are discussed. An extension of our technique for the study of low-temperature reactions with sympathetically cooled molecular ions (translational temperature T > 10 mK) is presented and first results on the charge-transfer reaction between OCS+ and ND3 are discussed. Finally, perspectives for further developments of our method are explored.
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Affiliation(s)
- Martin T Bell
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA, United Kingdom
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40
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Herschbach D. Molecular collisions, from warm to ultracold. Faraday Discuss 2010; 142:9-23; discussion 93-111. [PMID: 20151535 DOI: 10.1039/b910118g] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This introductory article contrasts molecular collisions, particularly reactive collisions, in the familiar "warm" domain with the ultracold regime where the relative deBroglie wavelengths become long compared with the range of interaction of the collision partners. Ultracold collisions have much greater sensitivity to entrance channel interactions, so offer the prospect of tuning by external fields to control onset of reaction. However, for ultracold collisions, kinematic constraints impose severe limitations on the observable dynamical properties. In the exit channel for appreciably exoergic reactions, the deBroglie wavelengths become short, so the exit dynamics are much like those for warm collisions. Reactions of alkali dimers, halides, and monoxide molecules are discussed that seem especially congenial for cold collision studies.
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Affiliation(s)
- Dudley Herschbach
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St., Cambridge, Massachusetts 02138, USA.
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41
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Schnell M, Meijer G. Cold Molecules: Preparation, Applications, and Challenges. Angew Chem Int Ed Engl 2009; 48:6010-31. [DOI: 10.1002/anie.200805503] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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42
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Schnell M, Meijer G. Kalte Moleküle: Herstellung, Anwendungen und Herausforderungen. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200805503] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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43
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Quéméner G, Balakrishnan N. Quantum calculations of H2–H2 collisions: From ultracold to thermal energies. J Chem Phys 2009; 130:114303. [DOI: 10.1063/1.3081225] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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44
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45
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Quéméner G, Balakrishnan N, Kendrick BK. Quantum dynamics of the O+OH→H+O2 reaction at low temperatures. J Chem Phys 2008; 129:224309. [DOI: 10.1063/1.3035904] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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46
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Willitsch S, Bell MT, Gingell AD, Softley TP. Chemical applications of laser- and sympathetically-cooled ions in ion traps. Phys Chem Chem Phys 2008; 10:7200-10. [PMID: 19060963 DOI: 10.1039/b813408c] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Ensembles of cold atomic and molecular ions in ion traps prepared at millikelvin temperatures by laser and sympathetic cooling have recently found considerable interest in both physics and chemistry. At very low temperatures the ions form ordered structures in the trap also known as "Coulomb crystals". Ion Coulomb crystals exhibit a range of intriguing properties which render them attractive systems for novel experiments in chemical dynamics, ultrahigh-resolution spectroscopy and quantum-information processing. In this article we review the methods used to prepare atomic and molecular ion Coulomb crystals and discuss some recent studies in mass spectrometry, low-temperature chemistry and precision spectroscopy to illustrate their scientific potential for chemical applications. Finally, we conclude with an outlook on outstanding challenges and prospective further developments in the field.
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Affiliation(s)
- Stefan Willitsch
- Department of Chemistry, University College London, 20 Gordon Street, London, UK WC1H 0AJ.
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47
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Tscherbul TV, Krems RV. Quantum theory of chemical reactions in the presence of electromagnetic fields. J Chem Phys 2008; 129:034112. [DOI: 10.1063/1.2954021] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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48
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Bovino S, Bodo E, Yurtsever E, Gianturco FA. Vibrational cooling of spin-stretched dimer states by He buffer gas: quantum calculations for Li2(a 3Sigma(u)+) at ultralow energies. J Chem Phys 2008; 128:224312. [PMID: 18554018 DOI: 10.1063/1.2933405] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The interaction between the triplet state of the lithium dimer, (7)Li(2), with (4)He is obtained from accurate ab initio calculations where the vibrational dependence of the potential is newly computed. Vibrational quenching dynamics within a coupled-channel quantum treatment is carried out at ultralow energies, and large differences in efficiency as a function of the initial vibrational state of the targets are found as one compares the triplet results with those of the singlet state of the same target.
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Affiliation(s)
- S Bovino
- Department of Chemistry and CNISM, University of Rome La Sapienza, Piazzale Aldo Moro 5, 00185 Rome, Italy
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49
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Quéméner G, Balakrishnan N. Cold and ultracold chemical reactions of F+HCl and F+DCl. J Chem Phys 2008; 128:224304. [DOI: 10.1063/1.2928804] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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50
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Willitsch S, Bell MT, Gingell AD, Procter SR, Softley TP. Cold Reactive Collisions between laser-cooled ions and velocity-selected neutral molecules. PHYSICAL REVIEW LETTERS 2008; 100:043203. [PMID: 18352269 DOI: 10.1103/physrevlett.100.043203] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2007] [Indexed: 05/26/2023]
Abstract
We report a new experimental method to study reactive ion-molecule collisions at very low temperatures. A source of laser-cooled ions in a linear Paul trap has been combined with a quadrupole-guide velocity selector to investigate the reaction of Ca+ with CH3F at collision energies E[over](coll)/k(B)> or =1 K with single-particle sensitivity. The technique represents a general approach to study reactive collisions between ions and polar molecules over a wide temperature range down to the cold regime.
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Affiliation(s)
- Stefan Willitsch
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford OX1 3TA, United Kingdom.
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