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Tóbiás R, Diouf ML, Cozijn FMJ, Ubachs W, Császár AG. All paths lead to hubs in the spectroscopic networks of water isotopologues H 216O and H 218O. Commun Chem 2024; 7:34. [PMID: 38365971 PMCID: PMC10873357 DOI: 10.1038/s42004-024-01103-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 01/08/2024] [Indexed: 02/18/2024] Open
Abstract
Network theory has fundamentally transformed our comprehension of complex systems, catalyzing significant advances across various domains of science and technology. In spectroscopic networks, hubs are the quantum states involved in the largest number of transitions. Here, utilizing network paths probed via precision metrology, absolute energies have been deduced, with at least 10-digit accuracy, for almost 200 hubs in the experimental spectroscopic networks of H216O and H218O. These hubs, lying on the ground vibrational states of both species and the bending fundamental of H216O, are involved in tens of thousands of observed transitions. Relying on the same hubs and other states, benchmark-quality line lists have been assembled, which supersede and improve, by three orders of magnitude, the accuracy of the massive amount of data reported in hundreds of papers dealing with Doppler-limited spectroscopy. Due to the omnipresence of water, these ultraprecise line lists could be applied to calibrate high-resolution spectra and serve ongoing and upcoming space missions.
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Affiliation(s)
- Roland Tóbiás
- Laboratory of Molecular Structure and Dynamics, Institute of Chemistry, ELTE Eötvös Loránd University and HUN-REN-ELTE Complex Chemical Systems Research Group, H-1117 Budapest, Pázmány Péter sétány 1/A, Hungary
| | - Meissa L Diouf
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| | - Frank M J Cozijn
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| | - Wim Ubachs
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands.
| | - Attila G Császár
- Laboratory of Molecular Structure and Dynamics, Institute of Chemistry, ELTE Eötvös Loránd University and HUN-REN-ELTE Complex Chemical Systems Research Group, H-1117 Budapest, Pázmány Péter sétány 1/A, Hungary.
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2
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Sitha S. Ortho-para interconversion of nuclear states of H 2O through replica transition state: prospect of quantum entanglement at homodromic Bjerrum defect site. J Mol Model 2023; 29:242. [PMID: 37436555 PMCID: PMC10338397 DOI: 10.1007/s00894-023-05646-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 07/01/2023] [Indexed: 07/13/2023]
Abstract
CONTEXT From a nuclear spin prospective, water exists as para and ortho nuclear spin isomers (isotopomers). Spin interconversions in isolated molecules of water are forbidden, but many recent reports have shown them to happen in bulk, through dynamic proton exchanges happening between interconnected networks of a large array of water molecules. In this contribution, a possible explanation for an unexpected slow or delayed interconversion of ortho-para water in ice observed in an earlier reported experiment is provided. Using the results of quantum mechanical investigations, we have discussed the roles played by Bjerrum defects in the dynamic proton exchanges and ortho-para spin state interconversions. We guess that at the sites of the Bjerrum defects, there are possibilities of quantum entanglements of states, through pairwise interactions. Based on the perfectly correlated exchange happening via a replica transition state, we speculate that it can have significant influences on ortho-para interconversions of water. We also conjecture that the overall ortho-para interconversion is not a continuous process, rather can be imagined to be happening serendipitously, but within the boundary of the rules of quantum mechanics. METHODS All computations were performed with Gaussian 09 program. B3LYP/6-31++G(d,p) methodology was used to compute all the stationary points. Further energy corrections were computed using CCSD(T)/aug-cc-pVTZ methodology. Intrinsic reaction coordinate (IRC) path computations were carried out for the transition states.
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Affiliation(s)
- Sanyasi Sitha
- Department of Chemical Sciences, APK Campus, University of Johannesburg, PO Box 524, Auckland Park, Johannesburg, 2006, South Africa.
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3
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Yachmenev A, Yang G, Zak E, Yurchenko S, Küpper J. The nuclear-spin-forbidden rovibrational transitions of water from first principles. J Chem Phys 2022; 156:204307. [DOI: 10.1063/5.0090771] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The water molecule occurs in two nuclear-spin isomers that differ by the value of the total nuclear spin of the hydrogen atoms, i.e., I = 0 for para-H2O and I = 1 for ortho-H2O. Spectroscopic transitions between rovibrational states of ortho and para water are extremely weak due to the tiny hyperfine nuclear-spin –rotation interaction of only ∼30 kHz and, so far, have not been observed. We report the first comprehensive theoretical investigation of the hyperfine effects and ortho–para transitions in [Formula: see text]O due to nuclear-spin –rotation and spin–spin interactions. We also present the details of our newly developed general variational approach to the simulation of hyperfine effects in polyatomic molecules. Our results for water suggest that the strongest ortho–para transitions with room-temperature intensities on the order of 10−31 cm/molecule are about an order of magnitude larger than previously predicted values and should be detectable in the mid-infrared ν2 and near-infrared 2 ν1 + ν2 and ν1 + ν2 + ν3 bands by current spectroscopy experiments.
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Affiliation(s)
- Andrey Yachmenev
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
- Center for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Guang Yang
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
- Department of Physics, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Emil Zak
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - Sergei Yurchenko
- Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London, United Kingdom
| | - Jochen Küpper
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
- Center for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- Department of Physics, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
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4
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Diouf ML, Tóbiás R, van der Schaaf TS, Cozijn FMJ, Salumbides EJ, Császár AG, Ubachs W. Ultraprecise relative energies in the (2 0 0) vibrational band of H 216O. Mol Phys 2022. [DOI: 10.1080/00268976.2022.2050430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Meissa L. Diouf
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit, Amsterdam, The Netherlands
| | - Roland Tóbiás
- Laboratory of Molecular Structure and Dynamics, Institute of Chemistry, ELTE Eötvös Loránd University and ELKH-ELTE Complex Chemical Systems Research Group, Budapest, Hungary
| | - Tom S. van der Schaaf
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit, Amsterdam, The Netherlands
| | - Frank M. J. Cozijn
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit, Amsterdam, The Netherlands
| | - Edcel J. Salumbides
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit, Amsterdam, The Netherlands
| | - Attila G. Császár
- Laboratory of Molecular Structure and Dynamics, Institute of Chemistry, ELTE Eötvös Loránd University and ELKH-ELTE Complex Chemical Systems Research Group, Budapest, Hungary
| | - Wim Ubachs
- Department of Physics and Astronomy, LaserLaB, Vrije Universiteit, Amsterdam, The Netherlands
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5
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Qu Q, Yurchenko SN, Tennyson J. A Method for the Variational Calculation of Hyperfine-Resolved Rovibronic Spectra of Diatomic Molecules. J Chem Theory Comput 2022; 18:1808-1820. [PMID: 35148098 PMCID: PMC9097294 DOI: 10.1021/acs.jctc.1c01244] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Indexed: 11/29/2022]
Abstract
An algorithm for the calculation of hyperfine structure and spectra of diatomic molecules based on the variational nuclear motion is presented. The hyperfine coupling terms considered are Fermi-contact, nuclear spin-electron spin dipole-dipole, nuclear spin-orbit, nuclear spin-rotation, and nuclear electric quadrupole interactions. Initial hyperfine-unresolved wave functions are obtained for a given set of potential energy curves and associated couplings by a variation solution of the nuclear-motion Schrödinger equation. Fully hyperfine-resolved parity-conserved rovibronic Hamiltonian matrices for a given final angular momentum, F, are constructed and then diagonalized to give hyperfine-resolved energies and wave functions. Electric transition dipole moment curves can then be used to generate a hyperfine-resolved line list by applying rigorous selection rules. The algorithm is implemented in Duo, which is a general program for calculating spectra of diatomic molecules. This approach is tested for NO and MgH, and the results are compared to experiment and shown to be consistent with those given by the well-used effective Hamiltonian code PGOPHER.
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Affiliation(s)
- Qianwei Qu
- Department of Physics and
Astronomy, University College London, WC1E 6BT London, U.K.
| | - Sergei N. Yurchenko
- Department of Physics and
Astronomy, University College London, WC1E 6BT London, U.K.
| | - Jonathan Tennyson
- Department of Physics and
Astronomy, University College London, WC1E 6BT London, U.K.
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6
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Wespiser C, Putaud T, Kalugina YN, Soldera A, Roy PN, Michaut X, Ayotte P. Ro-translational dynamics of confined water: I - The confined asymmetric rotor model. J Chem Phys 2022; 156:074304. [DOI: 10.1063/5.0079565] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
| | - Thomas Putaud
- Universite de Sherbrooke Departement de chimie, Canada
| | | | - Armand Soldera
- Department of Chemistry, Universite de Sherbrooke, Canada
| | - Pierre-Nicholas Roy
- Department of Chemistry, University of Waterloo Department of Chemistry, Canada
| | | | - Patrick Ayotte
- Département de Chimie, Universite de Sherbrooke Departement de chimie, Canada
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7
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Spectroscopic-network-assisted precision spectroscopy and its application to water. Nat Commun 2020; 11:1708. [PMID: 32249848 PMCID: PMC7136255 DOI: 10.1038/s41467-020-15430-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 03/05/2020] [Indexed: 11/09/2022] Open
Abstract
Frequency combs and cavity-enhanced optical techniques have revolutionized molecular spectroscopy: their combination allows recording saturated Doppler-free lines with ultrahigh precision. Network theory, based on the generalized Ritz principle, offers a powerful tool for the intelligent design and validation of such precision-spectroscopy experiments and the subsequent derivation of accurate energy differences. As a proof of concept, 156 carefully-selected near-infrared transitions are detected for H216O, a benchmark system of molecular spectroscopy, at kHz accuracy. These measurements, augmented with 28 extremely-accurate literature lines to ensure overall connectivity, allow the precise determination of the lowest ortho-H216O energy, now set at 23.794 361 22(25) cm−1, and 160 energy levels with similarly high accuracy. Based on the limited number of observed transitions, 1219 calibration-quality lines are obtained in a wide wavenumber interval, which can be used to improve spectroscopic databases and applied to frequency metrology, astrophysics, atmospheric sensing, and combustion chemistry. Precision-spectroscopy techniques can accurately measure lines in constrained frequency and intensity ranges. The authors propose a spectroscopic-network-assisted precision spectroscopy method by which transitions measured in a narrow range provide information in other, extended regions of the spectrum.
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8
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Horká-Zelenková V, Seyfang G, Dietiker P, Quack M. Nuclear Spin Symmetry Conservation Studied for Symmetric Top Molecules (CH3D, CHD3, CH3F, and CH3Cl) in Supersonic Jet Expansions. J Phys Chem A 2019; 123:6160-6174. [DOI: 10.1021/acs.jpca.9b02580] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Veronika Horká-Zelenková
- Laboratorium für Physikalische Chemie, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
- J. Heyrovský Institute of Physical Chemistry of the CAS, Dolejskova 2155/3, 182 23 Prague 8, Czech Republic
| | - Georg Seyfang
- Laboratorium für Physikalische Chemie, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
| | - Peter Dietiker
- Laboratorium für Physikalische Chemie, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
| | - Martin Quack
- Laboratorium für Physikalische Chemie, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
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9
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Sugimoto T, Nasu H, Arakawa I, Yamakawa K. Spectroscopic determination of interconversion rates among three nuclear spin isomers of methane in crystalline II. J Chem Phys 2019; 150:184302. [PMID: 31091910 DOI: 10.1063/1.5091070] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We measured infrared absorption spectra of crystalline II of CH4 and succeeded in detecting a prominent Q(2) peak in the ν3 vibrational region by rapid cooling after annealing as well as previously reported rovibrational and librational-vibrational peaks. The integral intensities of the R(0), R(1), and Q(2) peaks were found to show biexponential dependence on time. This clearly demonstrates the interconversion among the three nuclear-spin isomers occupying low-lying rotational levels. The two relaxation rates obtained by biexponential fitting were (0.48, 2.3), (1.1, 4.1), (2.3, 5.1), and (3.4, 15.3) in units of inverse hour (h-1) at 5.2, 6.0, 6.5, and 7.0 K, respectively.
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Affiliation(s)
- Takeru Sugimoto
- Department of Physics, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan
| | - Hirokazu Nasu
- Department of Physics, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan
| | - Ichiro Arakawa
- Department of Physics, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan
| | - Koichiro Yamakawa
- Department of Physics, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan
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10
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Tóbiás R, Furtenbacher T, Tennyson J, Császár AG. Accurate empirical rovibrational energies and transitions of H 216O. Phys Chem Chem Phys 2019; 21:3473-3495. [PMID: 30631873 DOI: 10.1039/c8cp05169k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Several significant improvements are proposed to the computational molecular spectroscopy protocol MARVEL (Measured Active Rotational-Vibrational Energy Levels) facilitating the inversion of a large set of measured rovibrational transitions to energy levels. The most important algorithmic changes include the use of groups of transitions, blocked by their estimated experimental (source segment) uncertainties, an inversion and weighted least-squares refinement procedure based on sequential addition of blocks of decreasing accuracy, the introduction of spectroscopic cycles into the refinement process, automated recalibration, synchronization of the combination difference relations to reduce residual uncertainties in the resulting dataset of empirical (MARVEL) energy levels, and improved classification of the lines and energy levels based on their accuracy and dependability. The resulting protocol, through handling a large number of measurements of similar accuracy, retains, or even improves upon, the best reported uncertainties of the spectroscopic transitions employed. To show its advantages, the extended MARVEL protocol is applied for the analysis of the complete set of highly accurate H216O transition measurements. As a result, almost 300 highly accurate energy levels of H216O are reported in the energy range of 0-6000 cm-1. Out of the 15 vibrational bands involved in accurately measured rovibrational transitions, the following three have definitely highly accurate empirical rovibrational energies of 8-10 digits of accuracy: (v1v2v3) = (0 0 0), (0 1 0), and (0 2 0), where v1, v2, and v3 stand for the symmetric stretch, bend, and antisymmetric stretch vibrational quantum numbers. The dataset of experimental rovibrational transitions and empirical rovibrational energy levels assembled during this study, both with improved uncertainties, is considerably larger and more accurate than the best previous datasets.
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Affiliation(s)
- Roland Tóbiás
- Laboratory of Molecular Structure and Dynamics, Institute of Chemistry, ELTE Eötvös Loránd University and MTA-ELTE Complex Chemical Systems Research Group, P.O. Box 32, H-1518 Budapest 112, Hungary
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11
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Orr BJ. Collision-induced rovibrational energy transfer in small polyatomic molecules: the role of intramolecular perturbations. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1490463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Brian J. Orr
- Department of Physics and Astronomy, MQ Photonics Research Centre, Macquarie University, Sydney, Australia
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12
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Manca Tanner C, Quack M, Schmidiger D. Nuclear spin symmetry conservation and relaxation of water (H216O) seeded in supersonic jets of argon and oxygen: measurements by cavity ring-down laser spectroscopy. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1484952] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
| | - Martin Quack
- Laboratorium für Physikalische Chemie, ETH Zürich, Zürich, Switzerland
| | - David Schmidiger
- Laboratorium für Physikalische Chemie, ETH Zürich, Zürich, Switzerland
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13
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Kanamori H, Dehghani ZT, Mizoguchi A, Endo Y. Detection of Microwave Transitions between Ortho and Para States in a Free Isolated Molecule. PHYSICAL REVIEW LETTERS 2017; 119:173401. [PMID: 29219458 DOI: 10.1103/physrevlett.119.173401] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Indexed: 06/07/2023]
Abstract
Microwave transitions between the ortho and para states of the S_{2}Cl_{2} molecule in a free isolated condition are observed for the first time. In the theoretical treatment, we derive eigenfunctions of an effective Hamiltonian including the ortho-para interaction to calculate the intensities and frequencies of forbidden ortho-para transitions in the cm-wave region and pick up some promising candidates for the spectroscopic detection. In the experiment, transitions of the S_{2}Cl_{2} molecule under a supersonic jet condition are observed with a Fourier transform microwave spectrometer. Seven hyperfine resolved rotational transitions including the lowest rotational level are detected as the ortho-para transitions at the predicted frequencies within the experimental errors. The observed intensities are about 10^{-3} times the allowed transitions, which are consistent with the predictions based on the intensity-borrowing model. This result suggests that the ortho-para conversion of this molecule occurs in a few thousand years through spontaneous emission even in a circumstance where molecular collisions occur rarely like in interstellar space.
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Affiliation(s)
- Hideto Kanamori
- Department of Physics, Tokyo Institute of Technology, Tokyo 152-8551, Japan
| | - Zeinab T Dehghani
- Department of Physics, Tokyo Institute of Technology, Tokyo 152-8551, Japan
| | - Asao Mizoguchi
- Department of Physics, Tokyo Institute of Technology, Tokyo 152-8551, Japan
| | - Yasuki Endo
- Department of Applied Chemistry, National Chiao, Tung University, Hsinchu 30010, Taiwan
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14
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Yachmenev A, Küpper J. Communication: General variational approach to nuclear-quadrupole coupling in rovibrational spectra of polyatomic molecules. J Chem Phys 2017; 147:141101. [PMID: 29031262 DOI: 10.1063/1.5002533] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A general algorithm for computing the quadrupole-hyperfine effects in the rovibrational spectra of polyatomic molecules is presented for the case of ammonia (NH3). The method extends the general variational approach TROVE [J. Mol. Spectrosc. 245, 126-140 (2007)] by adding the extra term in the Hamiltonian that describes the nuclear quadrupole coupling, with no inherent limitation on the number of quadrupolar nuclei in a molecule. We applied the new approach to compute the nitrogen-nuclear-quadrupole hyperfine structure in the rovibrational spectrum of NH314. These results agree very well with recent experimental spectroscopic data for the pure rotational transitions in the ground vibrational and ν2 states and the rovibrational transitions in the ν1, ν3, 2ν4, and ν1 + ν3 bands. The computed hyperfine-resolved rovibrational spectrum of ammonia will be beneficial for the assignment of experimental rovibrational spectra, further detection of ammonia in interstellar space, and studies of the proton-to-electron mass variation.
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Affiliation(s)
- Andrey Yachmenev
- Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Jochen Küpper
- Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
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15
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Abstract
Quantum mechanics builds large-scale graphs (networks): the vertices are the discrete energy levels the quantum system possesses, and the edges are the (quantum-mechanically allowed) transitions. Parts of the complete quantum mechanical networks can be probed experimentally via high-resolution, energy-resolved spectroscopic techniques. The complete rovibronic line list information for a given molecule can only be obtained through sophisticated quantum-chemical computations. Experiments as well as computations yield what we call spectroscopic networks (SN). First-principles SNs of even small, three to five atomic molecules can be huge, qualifying for the big data description. Besides helping to interpret high-resolution spectra, the network-theoretical view offers several ideas for improving the accuracy and robustness of the increasingly important information systems containing line-by-line spectroscopic data. For example, the smallest number of measurements necessary to perform to obtain the complete list of energy levels is given by the minimum-weight spanning tree of the SN and network clustering studies may call attention to "weakest links" of a spectroscopic database. A present-day application of spectroscopic networks is within the MARVEL (Measured Active Rotational-Vibrational Energy Levels) approach, whereby the transitions information on a measured SN is turned into experimental energy levels via a weighted linear least-squares refinement. MARVEL has been used successfully for 15 molecules and allowed to validate most of the transitions measured and come up with energy levels with well-defined and realistic uncertainties. Accurate knowledge of the energy levels with computed transition intensities allows the realistic prediction of spectra under many different circumstances, e.g., for widely different temperatures. Detailed knowledge of the energy level structure of a molecule coming from a MARVEL analysis is important for a considerable number of modeling efforts in chemistry, physics, and engineering.
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Affiliation(s)
- Attila G Császár
- Laboratory of Molecular Structure and Dynamics, Institute of Chemistry, Eötvös Loránd University , P.O. Box 32, H-1518 Budapest 112, Hungary.,MTA-ELTE Complex Chemical Systems Research Group , Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary
| | - Tibor Furtenbacher
- MTA-ELTE Complex Chemical Systems Research Group , Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary
| | - Péter Árendás
- MTA-ELTE Complex Chemical Systems Research Group , Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary.,Department of Algebra and Number Theory, Institute of Mathematics, Eötvös Loránd University , P.O. Box 120, H-1518 Budapest 112, Hungary
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16
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Hama T, Kouchi A, Watanabe N. Statistical ortho-to-para ratio of water desorbed from ice at 10 kelvin. Science 2016; 351:65-7. [DOI: 10.1126/science.aad4026] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Tetsuya Hama
- Institute of Low Temperature Science, Hokkaido University, Sapporo 060–0819, Japan
| | - Akira Kouchi
- Institute of Low Temperature Science, Hokkaido University, Sapporo 060–0819, Japan
| | - Naoki Watanabe
- Institute of Low Temperature Science, Hokkaido University, Sapporo 060–0819, Japan
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17
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Pershin SM. Ortho-para spin conversion of H2O in aqueous solutions as a quantum factor of the Konovalov paradox. Biophysics (Nagoya-shi) 2015. [DOI: 10.1134/s0006350914060165] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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18
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Pershin SM. Konovalov effect in low-concentration aqueous solutions: the role of ortho/para spin isomers of water. DOKLADY PHYSICAL CHEMISTRY 2014. [DOI: 10.1134/s0012501614030014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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19
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Manca Tanner C, Quack M, Schmidiger D. Nuclear Spin Symmetry Conservation and Relaxation in Water (1H216O) Studied by Cavity Ring-Down (CRD) Spectroscopy of Supersonic Jets. J Phys Chem A 2013; 117:10105-18. [DOI: 10.1021/jp400958f] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Carine Manca Tanner
- Laboratorium für Physikalische
Chemie, ETH Zürich, CH-8093 Zürich,
Switzerland
| | - Martin Quack
- Laboratorium für Physikalische
Chemie, ETH Zürich, CH-8093 Zürich,
Switzerland
| | - David Schmidiger
- Laboratorium für Physikalische
Chemie, ETH Zürich, CH-8093 Zürich,
Switzerland
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21
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Tennyson J. Accurate variational calculations for line lists to model the vibration-rotation spectra of hot astrophysical atmospheres. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2011. [DOI: 10.1002/wcms.94] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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22
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Sliter R, Gish M, Vilesov AF. Fast Nuclear Spin Conversion in Water Clusters and Ices: A Matrix Isolation Study. J Phys Chem A 2011; 115:9682-8. [DOI: 10.1021/jp201125k] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Russell Sliter
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Melissa Gish
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Andrey F. Vilesov
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
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23
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Lemeshko M, Friedrich B. Model Analysis of Rotationally Inelastic Ar + H2O Scattering in an Electric Field. J Phys Chem A 2009; 113:15055-63. [DOI: 10.1021/jp9051598] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mikhail Lemeshko
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Bretislav Friedrich
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
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24
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Buntkowsky G, Limbach HH, Walaszek B, Adamczyk A, Xu Y, Breitzke H, Schweitzer A, Gutmann T, Wächtler M, Amadeu N, Tietze D, Chaudret B. Mechanisms of Dipolar Ortho/Para-H2O Conversion in Ice. Z PHYS CHEM 2009. [DOI: 10.1524/zpch.2008.5359] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
In this paper a possible explanation for an unexpected ortho/para-water ratio in the gas clouds of comets is given. The description is based on the quantum-mechanical density matrix formalism and the spin temperature concept. Only the nuclear spin system is treated quantum-mechanically. Employing the model of a four spin system, created by two nearest neighbour water molecules, spin eigenstates and their dynamics under the influence of their mutual dipolar interactions are studied. It is shown that a fast conversion between ortho- and para-states occurs on a msec time scale, caused by the intermolecular homonuclear magnetic dipolar interaction. Moreover the spin eigenstates of water in an ice crystal are determined by magnetic dipolar interactions and are not given by normal ortho- and para-H2O states of gaseous water. As a result of this the spin temperature of gaseous water evaporated from ice depends strongly on its evaporation history and the ortho/para-ratio of water molecules are only an indirect measure of the temperature of ice crystals from where they descend. This result could explain the unexpected experimentally observed ortho/para-ratios in the clouds of comets.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Bruno Chaudret
- Laboratoire de Chimie de Doordination du CNRS, Toulouse Cedex 04, Frankreich
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25
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Abouaf-Marguin L, Vasserot AM, Pardanaud C, Michaut X. Nuclear spin conversion of water diluted in solid argon at 4.2K: Environment and atmospheric impurities effects. Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.09.014] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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26
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Lindsay C, Douberly G, Miller R. Rotational and vibrational dynamics of H2O and HDO in helium nanodroplets. J Mol Struct 2006. [DOI: 10.1016/j.molstruc.2005.09.025] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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27
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Limbach HH, Buntkowsky G, Matthes J, Gründemann S, Pery T, Walaszek B, Chaudret B. Novel Insights into the Mechanism of the Ortho/Para Spin Conversion of Hydrogen Pairs: Implications for Catalysis and Interstellar Water. Chemphyschem 2006; 7:551-4. [PMID: 16493700 DOI: 10.1002/cphc.200500559] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The phenomenon of exchange coupling is taken into account in the description of the magnetic nuclear spin conversion between bound ortho- and para-dihydrogen. This conversion occurs without bond breaking, in contrast to the chemical spin conversion. It is shown that the exchange coupling needs to be reduced so that the corresponding exchange barrier can increase and the given magnetic interaction can effectively induce a spin conversion. The implications for related molecules such as water are discussed. For ice, a dipolar magnetic conversion and for liquid water a chemical conversion are predicted to occur within the millisecond timescale. It follows that a separation of water into its spin isomers, as proposed by Tikhonov and Volkov (Science 2002, 296, 2363), is not feasible. Nuclear spin temperatures of water vapor in comets, which are smaller than the gas-phase equilibrium temperatures, are proposed to be diagnostic for the temperature of the ice or the dust surface from which the water was released.
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Affiliation(s)
- Hans-Heinrich Limbach
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustrasse 3, 14195 Berlin, Germany.
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28
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Ustynyuk YA, Gavrikov AV, Sergeyev NM. Catalytic homogeneous hydrogenation of compounds containing X ? O semipolar bonds (X = N, S, P) with para-hydrogen as a promising route for preparation of para-water. Phys Chem Chem Phys 2006; 8:5181-4. [PMID: 17203142 DOI: 10.1039/b610125a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The quantum-chemical simulation (DFT, PBE, TZ2p basis set) of the mechanism of catalytic hydrogenation of compounds containing R(n)X --> O semipolar bonds (R(n)X = N(2), Me(2)S, C(5)H(5)N, Ph(3)P) on the Wilkinson catalyst (Ph(3)P)(3)RhCl with para-hydrogen showed that this process proceeds with retention of proton nuclear spin correlation, which enables a principal possibility to synthesize para-H(2)O, i.e. the nuclear spin isomer of water with antiparallel proton spins, using this route.
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Affiliation(s)
- Yuri A Ustynyuk
- Department of Chemistry, M. V. Lomonosov Moscow State University, Leninskie Gory, 119899 Moscow, Russian Federation.
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29
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Scolnik Y, Portnaya I, Cogan U, Tal S, Haimovitz R, Fridkin M, Elitzur AC, Deamer DW, Shinitzky M. Subtle differences in structural transitions between poly-l- and poly-d-amino acids of equal length in water. Phys Chem Chem Phys 2006; 8:333-9. [PMID: 16482275 DOI: 10.1039/b513974k] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mirror-image asymmetric molecules, i.e., chiral isomers or enantiomers, are classically considered as chemically identical. Recent studies, however, have indicated that parity violation by the nuclear weak force induces a tiny energy difference between chiral isomers. Upon combination with a massive amplification process, expansion of this difference to a detectable macroscopic level may be achieved. Yet, experimental tests of this possibility, where one enantiomer is compared to the other in solution, are hampered by the possible presence of undetectable impurities. In this study we have overcome this problem by comparing structural and dynamic features of synthetic D- and L-polyglutamic acid and polylysine molecules each of 24 identical residues. In these water-soluble polypeptides helix formation is an intramolecular autocatalytic process amplified by each turn, which is actually unaffected by low level of putative impurities in the solvent. The helix and random coil configurations and their transition were determined in this study by circular dichroism (CD) and isothermal titration calorimetry (ITC) in water and deuterium oxide. Distinct differences in structure and transition energies between the enantiomeric polypeptides were detected by both CD and ITC when dissolved in water. Intriguingly, these differences were by and large abolished in deuterium oxide. Our findings suggest that deviation from physical invariance between the D- and L-polyamino acids is induced in part by different hydration in water which is eliminated in deuterium oxide. Based on the recent findings by Tikhonov and Volkov (V. I. Tikhonov and A. A. Volkov, Science 2002, 296, 2363) we suggest that ortho-H(2)O, which constitutes 75% of bulk H(2)O, has a preferential affinity to L-enantiomers. Differential hydration of enantiomers may have played a role in the selection of L-amino acids by early forms of life.
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Affiliation(s)
- Yosef Scolnik
- Weizmann Institute of Science, Rehovot 76100, Israel
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