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Liu QH, Tan Y, Cheng CF, Hu SM. Precision spectroscopy of molecular hydrogen. Phys Chem Chem Phys 2023; 25:27914-27925. [PMID: 37843424 DOI: 10.1039/d3cp03042c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
Precision measurements on the hydrogen molecule are of fundamental importance in understanding molecular theory. Comparison of accurate experimental data and theoretical results are used to test the quantum electrodynamics theory and determine physical constants used in the calculation. We review recent advances and perspectives in the precision spectroscopy of molecular hydrogen, representing state-of-the-art molecular spectroscopy methods and cutting-edge high-precision calculations.
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Affiliation(s)
- Qian-Hao Liu
- Department of Chemical Physics, University of Science and Technology of China, Hefei, 230026, China.
| | - Yan Tan
- Department of Chemical Physics, University of Science and Technology of China, Hefei, 230026, China.
| | - Cun-Feng Cheng
- Department of Chemical Physics, University of Science and Technology of China, Hefei, 230026, China.
| | - Shui-Ming Hu
- Department of Chemical Physics, University of Science and Technology of China, Hefei, 230026, China.
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2
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Pachucki K, Komasa J. Nonrelativistic energy of tritium-containing hydrogen molecule isotopologues. Mol Phys 2022. [DOI: 10.1080/00268976.2022.2040627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
| | - Jacek Komasa
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, Poznań, Poland
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3
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Lai KF, Salumbides EJ, Beyer M, Ubachs W. Precision measurement of quasi-bound resonances in H2 and the H + H scattering length. Mol Phys 2021. [DOI: 10.1080/00268976.2021.2018063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- K.-F. Lai
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit, Amsterdam, Netherlands
| | - E. J. Salumbides
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit, Amsterdam, Netherlands
| | - M. Beyer
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit, Amsterdam, Netherlands
| | - W. Ubachs
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit, Amsterdam, Netherlands
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4
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Somogyi W, Yurchenko SN, Yachmenev A. Calculation of electric quadrupole linestrengths for diatomic molecules: Application to the H 2, CO, HF, and O 2 molecules. J Chem Phys 2021; 155:214303. [PMID: 34879671 DOI: 10.1063/5.0063256] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a unified variational treatment of the electric quadrupole (E2) matrix elements, Einstein coefficients, and linestrengths for general open-shell diatomic molecules in the general purpose diatomic code Duo. Transformation relations between the Cartesian representation (typically used in electronic structure calculations) to the tensorial representation (required for spectroscopic applications) of the electric quadrupole moment components are derived. The implementation has been validated against accurate theoretical calculations and experimental measurements of quadrupole intensities of 1H2 available in the literature. We also present accurate electronic structure calculations of the electric quadrupole moment functions for the X1Σ+ electronic states of CO and HF, as well as for the a1Δg-b1Σg + quadrupole transition moment of O2 with the MRCI level of theory. Accurate infrared E2 line lists for 12C16O and 1H19F are provided. A demonstration of spectroscopic applications is presented by simulating E2 spectra for 12C16O, H19F, and 16O2 (Noxon a1Δg-b1Σg + band).
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Affiliation(s)
- W Somogyi
- Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London, United Kingdom
| | - S N Yurchenko
- Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London, United Kingdom
| | - A Yachmenev
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany and Center for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
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5
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Denisov GS, Denisov IG. More about properties of Morse oscillator. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 262:120111. [PMID: 34237688 DOI: 10.1016/j.saa.2021.120111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 06/21/2021] [Indexed: 06/13/2023]
Abstract
Using Birge-Sponer extrapolation we have analyzed the approximation of the potential of a real diatomic molecule by the Morse model, which implies a constant value of anharmonicity ωx. The real values of ωx*(v) for each vibrational level are estimated from transition frequencies between neighboring levels. The dependence of ωx* on the vibrational quantum number v up to dissociation is calculated from the literature data for the ground electronic state of H2, O2, Be2, Li2, ArXe, Xe2, Kr2 and the excited state of Li2. Characteristic features of deviations of the anharmonicity parameter x* - x from the Morse model are described.
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Affiliation(s)
- G S Denisov
- Department of Physics, St. Petersburg State University, 3 Uljanovskaya str., Petergof, St. Petersburg 198504, Russia
| | - I G Denisov
- Department of Biochemistry, University of Illinois, Urbana, IL 61801, USA.
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6
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Lai KF, Salumbides EJ, Ubachs W, Beyer M. Shape Resonances in H_{2} as Photolysis Reaction Intermediates. PHYSICAL REVIEW LETTERS 2021; 127:183001. [PMID: 34767422 DOI: 10.1103/physrevlett.127.183001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 09/02/2021] [Accepted: 09/27/2021] [Indexed: 06/13/2023]
Abstract
Shape resonances in H_{2}, produced as reaction intermediates in the photolysis of H_{2}S precursor molecules, are measured in a half-collision approach. Before disintegrating into two ground state H atoms, the reaction is quenched by two-photon Doppler-free excitation to the F electronically excited state of H_{2}. For J=13, 15, 17, 19, and 21, resonances with lifetimes in the range of nano- to milliseconds were observed with an accuracy of 30 MHz (1.4 mK). The experimental resonance positions are found to be in excellent agreement with theoretical predictions when nonadiabatic and quantum electrodynamical corrections are included. This is the first time such effects are observed in collisions between neutral atoms. From the potential energy curve of the H_{2} molecule, now tested at high accuracy over a wide range of internuclear separations, the s-wave scattering length for singlet H(1s)+H(1s) scattering is determined at a=0.2735_{31}^{39} a_{0}.
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Affiliation(s)
- K-F Lai
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit De Boelelaan 1081, 1081 HV Amsterdam, Netherlands
| | - E J Salumbides
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit De Boelelaan 1081, 1081 HV Amsterdam, Netherlands
| | - W Ubachs
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit De Boelelaan 1081, 1081 HV Amsterdam, Netherlands
| | - M Beyer
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit De Boelelaan 1081, 1081 HV Amsterdam, Netherlands
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7
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Lai KF, Hermann V, Trivikram TM, Diouf M, Schlösser M, Ubachs W, Salumbides EJ. Precision measurement of the fundamental vibrational frequencies of tritium-bearing hydrogen molecules: T 2, DT, HT. Phys Chem Chem Phys 2020; 22:8973-8987. [PMID: 32292981 DOI: 10.1039/d0cp00596g] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
High-resolution coherent Raman spectroscopic measurements of all three tritium-containing molecular hydrogen isotopologues T2, DT and HT were performed to determine the ground electronic state fundamental Q-branch (v = 0 → 1, ΔJ = 0) transition frequencies at accuracies of 0.0005 cm-1. An over hundred-fold improvement in accuracy over previous experiments allows the comparison with the latest ab initio calculations in the framework of non-adiabatic perturbation theory including nonrelativisitic, relativisitic and QED contributions. Excellent agreement is found between experiment and theory, thus providing a verification of the validity of the NAPT-framework for these tritiated species. While the transition frequencies were corrected for ac-Stark shifts, the contributions of non-resonant background as well as quantum interference effects between resonant features in the nonlinear spectroscopy were quantitatively investigated, also leading to corrections to the transition frequencies. Methods of saturated CARS with the observation of Lamb dips, as well as the use of continuous-wave radiation for the Stokes frequency were explored, that might pave the way for future higher-accuracy CARS measurements.
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Affiliation(s)
- K-F Lai
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
| | - V Hermann
- Tritium Laboratory Karlsruhe, Institute of Nuclear Physics, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - T M Trivikram
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
| | - M Diouf
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
| | - M Schlösser
- Tritium Laboratory Karlsruhe, Institute of Nuclear Physics, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - W Ubachs
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
| | - E J Salumbides
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
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8
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Abstract
Nonrelativistic energies of the deuterium molecule, accurate to 10-7-10-8 cm-1 for all levels located up to 8000 cm-1 above the ground state, are presented. The employed nonadiabatic James-Coolidge wave functions with angular factors enable the high accuracy to be reached regardless of vibrational or rotational quantum number. The derivative of the energy with respect to the deuteron-to-electron mass ratio is supplied for each level, which makes the results independent of the future changes in this physical parameter and will enable its determination from sufficiently accurate experimental data.
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Affiliation(s)
- Krzysztof Pachucki
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland.
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9
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Puchalski M, Komasa J, Czachorowski P, Pachucki K. Nonadiabatic QED Correction to the Dissociation Energy of the Hydrogen Molecule. PHYSICAL REVIEW LETTERS 2019; 122:103003. [PMID: 30932623 DOI: 10.1103/physrevlett.122.103003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Indexed: 06/09/2023]
Abstract
The quantum electrodynamic correction to the energy of the hydrogen molecule has been evaluated without expansion in the electron-proton mass ratio. The obtained results significantly improve the accuracy of theoretical predictions reaching the level of 1 MHz for the dissociation energy, in very good agreement with the parallel measurement [Hölsch et al., Phys. Rev. Lett. 122, 103002 (2019)PRLTAO0031-900710.1103/PhysRevLett.122.103002]. Molecular hydrogen has thus become a cornerstone of ultraprecise quantum chemistry, which opens perspectives for determination of fundamental physical constants from its spectra.
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Affiliation(s)
- Mariusz Puchalski
- Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89b, 61-614 Poznań, Poland
| | - Jacek Komasa
- Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89b, 61-614 Poznań, Poland
| | - Paweł Czachorowski
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Krzysztof Pachucki
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
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10
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Hölsch N, Beyer M, Salumbides EJ, Eikema KSE, Ubachs W, Jungen C, Merkt F. Benchmarking Theory with an Improved Measurement of the Ionization and Dissociation Energies of H_{2}. PHYSICAL REVIEW LETTERS 2019; 122:103002. [PMID: 30932670 DOI: 10.1103/physrevlett.122.103002] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 01/29/2019] [Indexed: 06/09/2023]
Abstract
The dissociation energy of H_{2} represents a benchmark quantity to test the accuracy of first-principles calculations. We present a new measurement of the energy interval between the EF ^{1}Σ_{g}^{+}(v=0,N=1) state and the 54p1_{1} Rydberg state of H_{2}. When combined with previously determined intervals, this new measurement leads to an improved value of the dissociation energy D_{0}^{N=1} of ortho-H_{2} that has, for the first time, reached a level of uncertainty that is 3 times smaller than the contribution of about 1 MHz resulting from the finite size of the proton. The new result of 35 999.582 834(11) cm^{-1} is in remarkable agreement with the theoretical result of 35 999.582 820(26) cm^{-1} obtained in calculations including high-order relativistic and quantum-electrodynamics corrections, as reported in the following Letter [M. Puchalski, J. Komasa, P. Czachorowski, and K. Pachucki, Phys. Rev. Lett. 122, 103003 (2019)PRLTAO0031-900710.1103/PhysRevLett.122.103003]. This agreement resolves a recent discrepancy between experiment and theory that had hindered a possible use of the dissociation energy of H_{2} in the context of the current controversy on the charge radius of the proton.
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Affiliation(s)
- Nicolas Hölsch
- Laboratorium für Physikalische Chemie, ETH-Zürich, 8093 Zürich, Switzerland
| | - Maximilian Beyer
- Laboratorium für Physikalische Chemie, ETH-Zürich, 8093 Zürich, Switzerland
| | - Edcel J Salumbides
- LaserLaB, Department of Physics and Astronomy, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Kjeld S E Eikema
- LaserLaB, Department of Physics and Astronomy, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Wim Ubachs
- LaserLaB, Department of Physics and Astronomy, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Christian Jungen
- Department of Physics and Astronomy, University College London, London, WC1E 6BT United Kingdom
| | - Frédéric Merkt
- Laboratorium für Physikalische Chemie, ETH-Zürich, 8093 Zürich, Switzerland
- LaserLaB, Department of Physics and Astronomy, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
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11
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Cheng CF, Hussels J, Niu M, Bethlem HL, Eikema KSE, Salumbides EJ, Ubachs W, Beyer M, Hölsch N, Agner JA, Merkt F, Tao LG, Hu SM, Jungen C. Dissociation Energy of the Hydrogen Molecule at 10^{-9} Accuracy. PHYSICAL REVIEW LETTERS 2018; 121:013001. [PMID: 30028156 DOI: 10.1103/physrevlett.121.013001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Indexed: 06/08/2023]
Abstract
The ionization energy of ortho-H_{2} has been determined to be E_{I}^{o}(H_{2})/(hc)=124 357.238 062(25) cm^{-1} from measurements of the GK(1,1)-X(0,1) interval by Doppler-free, two-photon spectroscopy using a narrow band 179-nm laser source and the ionization energy of the GK(1,1) state by continuous-wave, near-infrared laser spectroscopy. E_{I}^{o}(H_{2}) was used to derive the dissociation energy of H_{2}, D_{0}^{N=1}(H_{2}), at 35 999.582 894(25) cm^{-1} with a precision that is more than one order of magnitude better than all previous results. The new result challenges calculations of this quantity and represents a benchmark value for future relativistic and QED calculations of molecular energies.
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Affiliation(s)
- C-F Cheng
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit Amsterdam, de Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - J Hussels
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit Amsterdam, de Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - M Niu
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit Amsterdam, de Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - H L Bethlem
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit Amsterdam, de Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - K S E Eikema
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit Amsterdam, de Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - E J Salumbides
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit Amsterdam, de Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - W Ubachs
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit Amsterdam, de Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - M Beyer
- Laboratorium für Physikalische Chemie, ETH Zürich, 8093 Zürich, Switzerland
| | - N Hölsch
- Laboratorium für Physikalische Chemie, ETH Zürich, 8093 Zürich, Switzerland
| | - J A Agner
- Laboratorium für Physikalische Chemie, ETH Zürich, 8093 Zürich, Switzerland
| | - F Merkt
- Laboratorium für Physikalische Chemie, ETH Zürich, 8093 Zürich, Switzerland
| | - L-G Tao
- Hefei National Laboratory for Physical Sciences at Microscale, iChem center, University of Science and Technology China, Hefei, 230026 China
| | - S-M Hu
- Hefei National Laboratory for Physical Sciences at Microscale, iChem center, University of Science and Technology China, Hefei, 230026 China
| | - Ch Jungen
- Laboratoire Aimé Cotton du CNRS, Bâtiment 505, Université de Paris-Sud, F-91405 Orsay, France and Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom
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12
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Trivikram TM, Schlösser M, Ubachs W, Salumbides EJ. Relativistic and QED Effects in the Fundamental Vibration of T_{2}. PHYSICAL REVIEW LETTERS 2018; 120:163002. [PMID: 29756935 DOI: 10.1103/physrevlett.120.163002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Indexed: 06/08/2023]
Abstract
The hydrogen molecule has become a test ground for quantum electrodynamical calculations in molecules. Expanding beyond studies on stable hydrogenic species to the heavier radioactive tritium-bearing molecules, we report on a measurement of the fundamental T_{2} vibrational splitting (v=0→1) for J=0-5 rotational levels. Precision frequency metrology is performed with high-resolution coherent anti-Stokes Raman spectroscopy at an experimental uncertainty of 10-12 MHz, where sub-Doppler saturation features are exploited for the strongest transition. The achieved accuracy corresponds to a 50-fold improvement over a previous measurement, and it allows for the extraction of relativistic and QED contributions to T_{2} transition energies.
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Affiliation(s)
- T Madhu Trivikram
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - M Schlösser
- Tritium Laboratory Karlsruhe, Institute of Technical Physics, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - W Ubachs
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - E J Salumbides
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
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13
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Pachucki K, Komasa J. Nonadiabatic rotational states of the hydrogen molecule. Phys Chem Chem Phys 2018; 20:247-255. [PMID: 29200217 DOI: 10.1039/c7cp06516g] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
We present a new computational method for the determination of energy levels in four-particle systems like H2, HD, and HeH+ using explicitly correlated exponential basis functions and analytic integration formulas. In solving the Schrödinger equation, no adiabatic separation of the nuclear and electronic degrees of freedom is introduced. We provide formulas for the coupling between the rotational and electronic angular momenta, which enable calculations of arbitrary rotationally excited energy levels. To illustrate the high numerical efficiency of the method, we present the results for various states of the hydrogen molecule. The relative accuracy to which we determined the nonrelativistic energy reached the level of 10-12-10-13, which corresponds to an uncertainty of 10-7-10-8 cm-1.
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Affiliation(s)
- Krzysztof Pachucki
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland.
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14
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Altmann RK, Dreissen LS, Salumbides EJ, Ubachs W, Eikema KSE. Deep-Ultraviolet Frequency Metrology of H_{2} for Tests of Molecular Quantum Theory. PHYSICAL REVIEW LETTERS 2018; 120:043204. [PMID: 29437464 DOI: 10.1103/physrevlett.120.043204] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Indexed: 06/08/2023]
Abstract
Molecular hydrogen and its isotopic and ionic species are benchmark systems for testing quantum chemical theory. Advances in molecular energy structure calculations enable the experimental verification of quantum electrodynamics and potentially a determination of the proton charge radius from H_{2} spectroscopy. We measure the ground state energy in ortho-H_{2} relative to the first electronically excited state by Ramsey-comb laser spectroscopy on the EF^{1}Σ_{g}^{+}-X^{1}Σ_{g}^{+}(0,0) Q1 transition. The resulting transition frequency of 2 971 234 992 965(73) kHz is 2 orders of magnitude more accurate than previous measurements. This paves the way for a considerably improved determination of the dissociation energy (D_{0}) for fundamental tests with molecular hydrogen.
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Affiliation(s)
- R K Altmann
- LaserLaB, Department of Physics and Astronomy, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, Netherlands
| | - L S Dreissen
- LaserLaB, Department of Physics and Astronomy, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, Netherlands
| | - E J Salumbides
- LaserLaB, Department of Physics and Astronomy, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, Netherlands
| | - W Ubachs
- LaserLaB, Department of Physics and Astronomy, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, Netherlands
| | - K S E Eikema
- LaserLaB, Department of Physics and Astronomy, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, Netherlands
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15
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Przybytek M, Cencek W, Jeziorski B, Szalewicz K. Pair Potential with Submillikelvin Uncertainties and Nonadiabatic Treatment of the Halo State of the Helium Dimer. PHYSICAL REVIEW LETTERS 2017; 119:123401. [PMID: 29341636 DOI: 10.1103/physrevlett.119.123401] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Indexed: 06/07/2023]
Abstract
The pair potential for helium is computed with accuracy improved by an order of magnitude relative to the best previous determination. For the well region, its uncertainties are now below 1 millikelvin. The main improvement is due to the use of explicitly correlated wave functions at the nonrelativistic Born-Oppenheimer (BO) level of theory. The diagonal BO and the relativistic corrections are obtained from large full configuration interaction calculations. Nonadiabatic perturbation theory is used to predict the properties of the halo state of the helium dimer. Its binding energy and the average value of the interatomic distance are found to be 138.9(5) neV and 47.13(8) Å. The binding energy agrees with its first experimental determination of 151.9(13.3) neV [Zeller et al., Proc. Natl. Acad. Sci. U.S.A. 113, 14651 (2016)PNASA60027-842410.1073/pnas.1610688113].
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Affiliation(s)
- Michał Przybytek
- Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| | - Wojciech Cencek
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
| | - Bogumił Jeziorski
- Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| | - Krzysztof Szalewicz
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
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16
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Non-Born-Oppenheimer calculations of the rovibrational spectrum of H2 excited to the second rotational level. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2016.12.049] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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17
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Trivikram TM, Niu ML, Wcisło P, Ubachs W, Salumbides EJ. Precision measurements and test of molecular theory in highly excited vibrational states of H 2 ( v = 11). APPLIED PHYSICS. B, LASERS AND OPTICS 2016; 122:294. [PMID: 32336882 PMCID: PMC7154793 DOI: 10.1007/s00340-016-6570-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 11/04/2016] [Indexed: 06/08/2023]
Abstract
Accurate E F 1 Σ g + - X 1 Σ g + transition energies in molecular hydrogen were determined for transitions originating from levels with highly excited vibrational quantum number, v = 11, in the ground electronic state. Doppler-free two-photon spectroscopy was applied on vibrationally excited H 2 ∗ , produced via the photodissociation of H2S, yielding transition frequencies with accuracies of 45 MHz or 0.0015 cm-1. An important improvement is the enhanced detection efficiency by resonant excitation to autoionizing 7 p π electronic Rydberg states, resulting in narrow transitions due to reduced ac-Stark effects. Using known EF level energies, the level energies of X(v = 11, J = 1, 3-5) states are derived with accuracies of typically 0.002 cm-1. These experimental values are in excellent agreement with and are more accurate than the results obtained from the most advanced ab initio molecular theory calculations including relativistic and QED contributions.
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Affiliation(s)
- T. Madhu Trivikram
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - M. L. Niu
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - P. Wcisło
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziądzka 5, 87-100 Toruń, Poland
| | - W. Ubachs
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - E. J. Salumbides
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
- Department of Physics, University of San Carlos, 6000 Cebu City, Philippines
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18
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Pachucki K, Komasa J. Schrödinger equation solved for the hydrogen molecule with unprecedented accuracy. J Chem Phys 2016; 144:164306. [DOI: 10.1063/1.4948309] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Krzysztof Pachucki
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Jacek Komasa
- Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89b, 61-614 Poznań, Poland
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19
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Sommavilla M, Merkt F, Mezei JZ, Jungen C. Absorption, autoionization, and predissociation in molecular hydrogen: High-resolution spectroscopy and multichannel quantum defect theory. J Chem Phys 2016; 144:084303. [PMID: 26931698 DOI: 10.1063/1.4941920] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Absorption and photoionization spectra of H2 have been recorded at a resolution of 0.09 and 0.04 cm(-1), respectively, between 125,600 cm(-1) and 126,000 cm(-1). The observed Rydberg states belong to series (n = 10 - 14) converging on the first vibrationally excited level of the X (2)Σ(g)(+) state of H2(+), and of lower members of series converging on higher vibrational levels. The observed resonances are characterized by the competition between autoionization, predissociation, and fluorescence. The unprecedented resolution of the present experimental data leads to a full characterization of the predissociation/autoionization profiles of many resonances that had not been resolved previously. Multichannel quantum defect theory is used to predict the line positions, widths, shapes, and intensities of the observed spectra and is found to yield quantitative agreement using previously determined quantum defect functions as the unique set of input parameters.
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Affiliation(s)
- M Sommavilla
- Laboratorium für Physikalische Chemie, ETH-Zürich, 8093 Zürich, Switzerland
| | - F Merkt
- Laboratorium für Physikalische Chemie, ETH-Zürich, 8093 Zürich, Switzerland
| | - J Zs Mezei
- Laboratoire Ondes et Milieux Complexes, UMR 6294 CNRS and Université du Havre, 25, rue Philippe Lebon, BP 540, F-76058 Le Havre, France
| | - Ch Jungen
- Laboratoire Aimé Cotton du CNRS, Bâtiment 505, Université de Paris-Sud, F-91405 Orsay, France
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20
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Niu ML, Salumbides EJ, Ubachs W. Communication: Test of quantum chemistry in vibrationally hot hydrogen molecules. J Chem Phys 2015; 143:081102. [PMID: 26328810 DOI: 10.1063/1.4929568] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Precision measurements are performed on highly excited vibrational quantum states of molecular hydrogen. The v = 12, J = 0 - 3 rovibrational levels of H2 (X(1)Σg (+)), lying only 2000 cm(-1) below the first dissociation limit, were populated by photodissociation of H2S and their level energies were accurately determined by two-photon Doppler-free spectroscopy. A comparison between the experimental results on v = 12 level energies with the best ab initio calculations shows a good agreement, where the present experimental accuracy of 3.5 × 10(-3) cm(-1) is more precise than theory, hence providing a gateway to further test theoretical advances in this benchmark quantum system.
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Affiliation(s)
- M L Niu
- Department of Physics and Astronomy and LaserLaB, VU University, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - E J Salumbides
- Department of Physics and Astronomy and LaserLaB, VU University, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - W Ubachs
- Department of Physics and Astronomy and LaserLaB, VU University, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
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