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Trenins G, Meuser L, Bertschi H, Vavourakis O, Flütsch R, Richardson JO. Exact tunneling splittings from symmetrized path integrals. J Chem Phys 2023; 159:034108. [PMID: 37466233 DOI: 10.1063/5.0158879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 06/13/2023] [Indexed: 07/20/2023] Open
Abstract
We develop a new simulation technique based on path-integral molecular dynamics for calculating ground-state tunneling splitting patterns from ratios of symmetrized partition functions. In particular, molecular systems are rigorously projected onto their J = 0 rotational state by an "Eckart spring" that connects two adjacent beads in a ring polymer. Using this procedure, the tunneling splitting can be obtained from thermodynamic integration at just one (sufficiently low) temperature. Converged results are formally identical to the values that would have been obtained by solving the full rovibrational Schrödinger equation on a given Born-Oppenheimer potential energy surface. The new approach is showcased with simulations of hydronium and methanol, which are in good agreement with wavefunction-based calculations and experimental measurements. The method will be of particular use for the study of low-barrier methyl rotations and other floppy modes, where instanton theory is not valid.
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Affiliation(s)
- George Trenins
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
| | - Lars Meuser
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
| | - Hannah Bertschi
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
| | - Odysseas Vavourakis
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
| | - Reto Flütsch
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
| | - Jeremy O Richardson
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
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2
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Nejad A, Crittenden DL. On the separability of large-amplitude motions in anharmonic frequency calculations. Phys Chem Chem Phys 2020; 22:20588-20601. [PMID: 32966420 DOI: 10.1039/d0cp03515g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nuclear vibrational theories based upon the Watson Hamiltonian are ubiquitous in quantum chemistry, but are generally unable to model systems in which the wavefunction can delocalise over multiple energy minima, i.e. molecules that have low-energy torsion and inversion barriers. In a 2019 Chemical Reviews article, Puzzarini et al. note that a common workaround is to simply decouple these problematic modes from all other vibrations in the system during anharmonic frequency calculations. They also point out that this approximation can be "ill-suited", but do not quantify the errors introduced. In this work, we present the first systematic investigation into how separating out or constraining torsion and inversion vibrations within potential energy surface (PES) expansions affects the accuracy of computed fundamental wavenumbers for the remaining vibrational modes, using a test set of 19 tetratomic molecules for which high quality analytic potential energy surfaces and fully-coupled anharmonic reference fundamental frequencies are available. We find that the most effective and efficient strategy is to remove the mode in question from the PES expansion entirely. This introduces errors of up to +10 cm-1 in stretching fundamentals that would otherwise couple to the dropped mode, and ±5 cm-1 in all other fundamentals. These errors are approximately commensurate with, but not necessarily additional to, errors due to the choice of electronic structure model used in constructing spectroscopically accurate PES.
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Affiliation(s)
- Arman Nejad
- Institute of Physical Chemistry, University of Göttingen, Tammannstr. 6, D-37077 Göttingen, Germany.
| | - Deborah L Crittenden
- School of Physical and Chemical Sciences, University of Canterbury, Christchurch, New Zealand
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Nandi A, Qu C, Bowman JM. Diffusion Monte Carlo Calculations of Zero-Point Energies of Methanol and Deuterated Methanol. J Comput Chem 2019; 40:328-332. [PMID: 30284291 DOI: 10.1002/jcc.25601] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Revised: 08/23/2018] [Accepted: 08/24/2018] [Indexed: 11/05/2022]
Abstract
Diffusion Monte Carlo (DMC) simulations have been used to obtain quantum zero-point energies of methanol and all its isotopologs and isotopomers, using a new, accurate semi-global potential energy surface. This potential energy surface is a precise, permutationally invariant fit to 6676 ab initio energies, obtained at the CCSD(T)-F12b/aug-cc-pVDZ level of theory. Quantum zero-point energies of deuterated methanol isotopomers are very close to each other and so a simple statistical argument can be used to estimate the populations of each isotopomer at very low-temperatures. The DMC simulations also indicate that there is virtually zero probability for H/D exchange in the zero-point state. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Apurba Nandi
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322
| | - Chen Qu
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322
| | - Joel M Bowman
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322
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Huang M, Miller TA, McCoy AB, Hsu KH, Huang YH, Lee YP. Modeling the CH Stretch/Torsion/Rotation Couplings in Methyl Peroxy (CH3OO). J Phys Chem A 2017; 121:9619-9630. [DOI: 10.1021/acs.jpca.7b10784] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Meng Huang
- Department
of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Terry A. Miller
- Department
of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Anne B. McCoy
- Department
of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Kuo-Hsiang Hsu
- Department
of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 30010, Taiwan
| | - Yu-Hsuan Huang
- Department
of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 30010, Taiwan
| | - Yuan-Pern Lee
- Department
of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 30010, Taiwan
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
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Dawadi MB, Thapaliya BP, Perry DS. An extended E⊗e Jahn-Teller Hamiltonian for large-amplitude motion: Application to vibrational conical intersections in CH 3SH and CH 3OH. J Chem Phys 2017; 147:044306. [PMID: 28764373 DOI: 10.1063/1.4994699] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
An extended E⊗e Jahn-Teller Hamiltonian is presented for the case where the (slow) nuclear motion extends far from the symmetry point and may be described approximately as motion on a sphere. Rather than the traditional power series expansion in the displacement from the C3v symmetry point, an expansion in the spherical harmonics is employed. Application is made to the vibrational Jahn-Teller effect in CH3XH, with X = S, O, where the equilibrium CXH angles are 83° and 72°, respectively. In addition to the symmetry-required conical intersection (CI) at the C3v symmetry point, ab initio calculations reveal sets of six symmetry-allowed vibrational CIs in each molecule. The CIs for each molecule are arranged differently in the large-amplitude space, and that difference is reflected in the infrared spectra. The CIs in CH3SH are found in both eclipsed and staggered geometries, whereas those for CH3OH are found only in the eclipsed geometry near the torsional saddle point. This difference between the two molecules is reflected in the respective high-resolution spectra in the CH stretch fundamental region.
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Affiliation(s)
- Mahesh B Dawadi
- Department of Chemistry, The University of Akron, Akron, Ohio 44325-3601, USA
| | - Bishnu P Thapaliya
- Department of Chemistry, The University of Akron, Akron, Ohio 44325-3601, USA
| | - David S Perry
- Department of Chemistry, The University of Akron, Akron, Ohio 44325-3601, USA
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Biswal HS, Bhattacharyya S, Bhattacherjee A, Wategaonkar S. Nature and strength of sulfur-centred hydrogen bonds: laser spectroscopic investigations in the gas phase and quantum-chemical calculations. INT REV PHYS CHEM 2015. [DOI: 10.1080/0144235x.2015.1022946] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Mosley JD, Young JW, Huang M, McCoy AB, Duncan MA. Infrared spectroscopy of the methanol cation and its methylene-oxonium isomer. J Chem Phys 2015; 142:114301. [DOI: 10.1063/1.4914146] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- J. D. Mosley
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - J. W. Young
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - M. Huang
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - A. B. McCoy
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - M. A. Duncan
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
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Dawadi MB, Bhatta RS, Perry DS. Contrasting patterns of coupling between the CH stretches and the large-amplitude motions in the molecules, CH3NH2, CH3OH2+ and CH3CH2. Chem Phys Lett 2015. [DOI: 10.1016/j.cplett.2015.02.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Raston PL, Douberly GE, Jäger W. Single and double resonance spectroscopy of methanol embedded in superfluid helium nanodroplets. J Chem Phys 2014; 141:044301. [DOI: 10.1063/1.4887348] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Dawadi MB, Bhatta RS, Perry DS. Torsion–Inversion Tunneling Patterns in the CH-Stretch Vibrationally Excited States of the G12 Family of Molecules Including Methylamine. J Phys Chem A 2013; 117:13356-67. [DOI: 10.1021/jp406668w] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mahesh B. Dawadi
- Department
of Chemistry, The University of Akron, Akron, Ohio 44325, United
States
| | - Ram S. Bhatta
- Department
of Chemistry, The University of Akron, Akron, Ohio 44325, United
States
| | - David S. Perry
- Department
of Chemistry, The University of Akron, Akron, Ohio 44325, United
States
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12
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Dawadi MB, Michael Lindsay C, Chirokolava A, Perry DS, Xu LH. Novel patterns of torsion-inversion-rotation energy levels in the ν11 asymmetric CH-stretch spectrum of methylamine. J Chem Phys 2013; 138:104305. [DOI: 10.1063/1.4794157] [Citation(s) in RCA: 11] [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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13
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Bhattacherjee A, Matsuda Y, Fujii A, Wategaonkar S. The Intermolecular SH⋅⋅⋅Y (Y=S,O) Hydrogen Bond in the H2S Dimer and the H2S-MeOH Complex. Chemphyschem 2013; 14:905-14. [DOI: 10.1002/cphc.201201012] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Indexed: 11/07/2022]
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Affiliation(s)
- Chen Qu
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University , Atlanta, Georgia, USA
| | - Joel M. Bowman
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University , Atlanta, Georgia, USA
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Morrison AM, Liang T, Douberly GE. Automation of an "Aculight" continuous-wave optical parametric oscillator. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2013; 84:013102. [PMID: 23387632 DOI: 10.1063/1.4776179] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We report the automation of a continuous-wave, singly resonant, optical parametric oscillator (Lockheed-Martin Aculight ARGOS 2400-SF-15). This commercially available optical parametric oscillator (OPO) is capable of producing >1 W of continuously tunable idler output between 2.2 and 4.6 μm. An algorithm based on the feedback from a high accuracy wavemeter is implemented to synchronize three separate OPO tuning elements; the translation of a fan-out type periodically poled lithium niobate crystal, the rotation of an intracavity etalon, and the continuous tuning of the pump and idler wavelengths via piezoelectric strain of the tunable fiber pump laser. This allows for several hundred wavenumbers of efficient, automatic, continuous tuning of the idler wave. Continuous feedback from the wavemeter limits the absolute frequency accuracy to ±20 MHz. The broad, automatic tuning of the OPO is demonstrated via its implementation as a probe laser for the infrared action spectroscopy of methanol solvated in helium nanodroplets. LabVIEW virtual instruments for the automation of this OPO laser system are reported, along with detailed schematics of the associated hardware developed at the University of Georgia.
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Fu L, Han HL, Lee YP. Infrared absorption of methanethiol clusters (CH3SH)n, n = 2–5, recorded with a time-of-flight mass spectrometer using IR depletion and VUV ionization. J Chem Phys 2012; 137:234307. [DOI: 10.1063/1.4770227] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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17
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Twagirayezu S, Wang X, Perry DS, Neill JL, Muckle MT, Pate BH, Xu LH. IR and FTMW-IR Spectroscopy and Vibrational Relaxation Pathways in the CH Stretch Region of CH3OH and CH3OD. J Phys Chem A 2011; 115:9748-63. [DOI: 10.1021/jp202020u] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Xiaoliang Wang
- Department of Chemistry, The University of Akron, Akron, Ohio 44325, United States
| | - David S. Perry
- Department of Chemistry, The University of Akron, Akron, Ohio 44325, United States
| | - Justin L. Neill
- Department of Chemistry, University of Virginia, McCormick Road, Charlottesville, Virginia 22904, United States
| | - Matt T. Muckle
- Department of Chemistry, University of Virginia, McCormick Road, Charlottesville, Virginia 22904, United States
| | - Brooks H. Pate
- Department of Chemistry, University of Virginia, McCormick Road, Charlottesville, Virginia 22904, United States
| | - Li-Hong Xu
- Department of Physics, Centre for Laser, Atomic and Molecular Studies (CLAMS), University of New Brunswick, Saint John, New Brunswick E2L 4L5, Canada
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Han HL, Camacho C, Witek HA, Lee YP. Infrared absorption of methanol clusters (CH3OH)n with n = 2−6 recorded with a time-of-flight mass spectrometer using infrared depletion and vacuum-ultraviolet ionization. J Chem Phys 2011; 134:144309. [DOI: 10.1063/1.3572225] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Twagirayezu S, Clasp TN, Perry DS, Neill JL, Muckle MT, Pate BH. Vibrational Coupling Pathways in Methanol As Revealed by Coherence-Converted Population Transfer Fourier Transform Microwave Infrared Double-Resonance Spectroscopy. J Phys Chem A 2010; 114:6818-28. [DOI: 10.1021/jp1019735] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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20
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Perry DS, Miller A, Amyay† B, Fayt A, Herman M. Vibration–rotation alchemy in acetylene (12C2H2), at low vibrational excitation: from high resolution spectroscopy to fast intramolecular dynamics. Mol Phys 2010. [DOI: 10.1080/00268971003660874] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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21
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HÄNNINEN VESA, HALONEN LAURI. Calculation of spectroscopic parameters and vibrational overtones of methanol. Mol Phys 2009. [DOI: 10.1080/00268970310001598740] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- VESA HÄNNINEN
- a Laboratory of Physical Chemistry , University of Helsinki , PO Box 55 (A.I. Virtasen aukio I), FIN-00014 , Finland
| | - LAURI HALONEN
- a Laboratory of Physical Chemistry , University of Helsinki , PO Box 55 (A.I. Virtasen aukio I), FIN-00014 , Finland
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Perchard J, Romain F, Bouteiller Y. Determination of vibrational parameters of methanol from matrix-isolation infrared spectroscopy and ab initio calculations. Part 1 – Spectral analysis in the domain 11000–200cm−1. Chem Phys 2008. [DOI: 10.1016/j.chemphys.2007.10.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Bowman JM, Huang X, Handy NC, Carter S. Vibrational Levels of Methanol Calculated by the Reaction Path Version of MULTIMODE, Using an ab initio, Full-Dimensional Potential. J Phys Chem A 2007; 111:7317-21. [PMID: 17439199 DOI: 10.1021/jp070398m] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
An accurate potential energy surface has been determined for methanol from ab initio potential data at the CCSD(T) level of theory with an aug-cc-pVTZ basis. The resulting potential function is valid over all twelve vibrational degrees of freedom for all near-equilibrium and torsional configurations. A torsional reaction path has been derived for this potential, from which the low-lying vibrational levels of methanol have been calculated by the reaction path version of MULTIMODE. Comparisons with experiment and other calculations are made.
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Affiliation(s)
- Joel M Bowman
- Cherry L. Emerson Center for Scientific Computation, Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA.
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Clasp TN, Perry DS. Torsion-vibration coupling in methanol: The adiabatic approximation and intramolecular vibrational redistribution scaling. J Chem Phys 2006; 125:104313. [PMID: 16999532 DOI: 10.1063/1.2336431] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The four-dimensional model Hamiltonian of Wang and Perry [J. Chem. Phys. 109, 10795 (1998)] is used to compare the approximate adiabatic separation of the torsion and CH stretches in methanol to an exact solution of the same Hamiltonian. The adiabatic approximation accounts for the pattern of the energy levels in the lowest torsional states, including the inverted tunneling splittings, but does not account for the pattern of systematic two- and four-fold near degeneracies at high torsional excitation. In the adiabatic basis, the nonadiabatic couplings mix the torsional and vibrational degrees of freedom and hence are a source for intramolecular vibrational redistribution (IVR). These IVR matrix elements are found to decrease by only a factor of 2 or 3 with each higher coupling order, in agreement with the results of Pearman and Gruebele [Z. Phys. Chem. Munich 214, 1439 (2000)]. This gentle scaling behavior, which contrasts with a steeper falloff with coupling order in more rigid molecules, points to a more important role for direct high-order couplings in torsional molecules. In this model, the scaling behavior derives from a single coupling term that is low order in the torsional angular momentum in combination with one-dimensional torsional functions that include contributions from many torsional angular momenta.
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Affiliation(s)
- Trocia N Clasp
- Department of Chemistry, The University of Akron, Akron, OH 44325-3601, USA
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Lee YP, Wu YJ, Lees RM, Xu LH, Hougen JT. Internal Rotation and Spin Conversion of CH
3
OH in Solid para-Hydrogen. Science 2006; 311:365-8. [PMID: 16424336 DOI: 10.1126/science.1121300] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The quantum solid para-hydrogen (p-H2) has recently proven useful in matrix isolation spectroscopy. Spectral lines of compounds embedded in this host are unusually narrow, and several species have been reported to rotate in p-H2. We found that a p-H2 matrix inhibits rotation of isolated methanol (CH3OH) but still allows internal rotation about the C-O bond, with splittings of the E/A torsional doublet in internal rotation-coupled vibrational modes that are qualitatively consistent with those for CH3OH in the gaseous phase. This simplified high-resolution spectrum further revealed the slow conversion of nuclear spin symmetry from species E to species A in the host matrix, offering potential insight into nuclear spin conversion in astrophysical sources.
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Affiliation(s)
- Yuan-Pern Lee
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta-Hsueh Road, Hsinchu 30010, Taiwan.
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Lattanzi * F, Di Lauro C. Vibrational symmetry classification and torsional tunneling splitting patterns in G6(EM), G12, and G36(EM) molecules. Mol Phys 2005. [DOI: 10.1080/00268970412331333410] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Rueda D, Boyarkin OV, Rizzo TR, Chirokolava A, Perry DS. Vibrational overtone spectroscopy of jet-cooled methanol from 5000 to 14 000 cm−1. J Chem Phys 2005; 122:44314. [PMID: 15740255 DOI: 10.1063/1.1833353] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Spectra of jet-cooled methanol in the overtone and combination region from 5000 to 14 000 cm(-1) have been obtained by means of infrared laser-assisted photofragment spectroscopy. Many of the observed features are assigned to combination bands of the type nnu(1)+nu(6), nnu(1)+nu(8), and nnu(1)+nu(6)+nu(8) (n=1,2,3), where nu(1) is the OH stretch, nu(6) is the OH bend, and nu(8) is the CO stretch. These bands show sharp torsion-rotation structure with features as narrow as 0.1 cm(-1). We also observe CH stretch overtones that are weaker than the OH containing combination bands and lack distinct torsion-rotation structure above v(CH)=2. The extent of observed structure on these bands allows us to place limits on the intramolecular vibrational energy redistribution decay rates in the upper vibrational states. We report a global fit of the observed band centers to a simple expression involving low-order anharmonicity constants.
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Affiliation(s)
- David Rueda
- Laboratoire de Chimie Physique Moléculaire, EPFL, Station-6, CH-1015 Lausanne, Switzerland.
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Castillo-Chará J, Sibert EL. Full dimensional theoretical study of the torsion-vibration eigenstates and torsional splittings of CH3OH. J Chem Phys 2003. [DOI: 10.1063/1.1624595] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
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Fehrensen B, Luckhaus D, Quack M, Willeke M, Rizzo TR. Ab initiocalculations of mode selective tunneling dynamics in 12CH3OH and 13CH3OH. J Chem Phys 2003. [DOI: 10.1063/1.1573632] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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31
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GEORGES R, BONNAMY A, BENIDAR A, DECROI M, BOISSOLES J. FTIR free-jet set-up for the high resolution spectroscopic investigation of condensable species. Mol Phys 2002. [DOI: 10.1080/00268970110117980] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Mumma MJ, Dello Russo N, DiSanti MA, Magee-Sauer K, Novak RE, Brittain S, Rettig T, McLean IS, Reuter DC, Xu LH. Organic Composition of C/1999 S4 (LINEAR): A Comet Formed Near Jupiter? Science 2001; 292:1334-9. [PMID: 11359002 DOI: 10.1126/science.1058929] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
In the current paradigm, Oort cloud comets formed in the giant planets' region of the solar nebula, where temperatures and other conditions varied greatly. The measured compositions of four such comets (Halley, Hyakutake, Hale-Bopp, and Lee) are consistent with formation from interstellar ices in the cold nebular region beyond Uranus. The composition of comet C/1999 S4 (LINEAR) differs greatly, which suggests that its ices condensed from processed nebular gas, probably in the Jupiter-Saturn region. Its unusual organic composition may require reevaluation of the prebiotic organic material delivered to the young Earth by comets.
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Affiliation(s)
- M J Mumma
- Laboratory for Extraterrestrial Physics, Code 690, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
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Hougen JT. Torsional Splittings in Small-Amplitude Vibrational Fundamental States of Methanol-Type Molecules. JOURNAL OF MOLECULAR SPECTROSCOPY 2001; 207:60-65. [PMID: 11336521 DOI: 10.1006/jmsp.2001.8329] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Group-theoretical methods are used to show that inverted torsional splittings in fundamental levels of small-amplitude vibrations of methanol-like molecules can be parameterized and understood in terms of the energy level patterns induced when a pair of high-barrier torsionally split components of given v(t) and (t)A+(t)E symmetry species in the molecular symmetry group G(6) is allowed to interact with small-amplitude vibrational modes of symmetry (v)E. Such doubly degenerate (v)E vibrational modes arise rather naturally in G(6) (isomorphic with the point-group C(3v)) for those methyl-group vibrations in point-group-C(s) asymmetric tops such as CH(3)-CHO that are analogs of the degenerate methyl-group stretch, bend, and rocking vibrations in point-group-C(3v) symmetric tops such as CH(3)-C identical withC-H. The present group-theoretical treatment is somewhat different from, but (as a comparison of model parameters shows) still fundamentally similar to, the recent local mode explanation of inverted torsional splittings in the C-H stretching fundamental region in methanol. Copyright 2001 Academic Press.
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Affiliation(s)
- Jon T. Hougen
- Optical Technology Division, National Institute of Standards and Technology, Gaithersburg, Maryland, 20899-8441
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Chirokolava A, Perry DS, Boyarkin OV, Schmid M, Rizzo TR. Intramolecular energy transfer in highly vibrationally excited methanol. IV. Spectroscopy and dynamics of 13CH3OH. J Chem Phys 2000. [DOI: 10.1063/1.1323507] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
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Brutschy B. The structure of microsolvated benzene derivatives and the role of aromatic substituents. Chem Rev 2000; 100:3891-920. [PMID: 11749333 DOI: 10.1021/cr990055n] [Citation(s) in RCA: 276] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- B Brutschy
- Institut für Physikalische und Theoretische Chemie, J. W. Goethe-Universität Frankfurt, Marie-Curie-Str. 11, D-60439 Frankfurt a. M., Germany
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Chirokolava A, Perry DS, Xu LH. Sub-Doppler Infrared Spectra of the OH-Stretch Fundamental of (13)C-Methanol. JOURNAL OF MOLECULAR SPECTROSCOPY 2000; 203:320-329. [PMID: 10986144 DOI: 10.1006/jmsp.2000.8194] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
High-resolution infrared spectra of the (13)C-methanol OH stretching band, nu(1), were obtained by slit-jet absorption spectroscopy at a rotational temperature of 12-15 K. Twenty-eight subbands were assigned within the range of upper state quantum numbers, K' = 0 to 2 and J' = 0 to 10. The upper state energy levels are heavily perturbed; about half of the assigned subbands were found to be split by perturbations with matrix elements in the range 1-3 cm(-1). The doubled lines were deperturbed and together with the "unperturbed" lines were fitted to a global torsion-rotation Hamiltonian with root-mean-square deviation of 0.41 cm(-1) to yield a torsional barrier height of approximately 405 cm(-1) in the vibrationally excited state. Copyright 2000 Academic Press.
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Affiliation(s)
- A Chirokolava
- Department of Chemistry, University of Akron, Akron, Ohio, 44325-3601
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Xu LH. Can a local mode picture account for vibration–torsion coupling? Ab initio test based on torsional variation of methyl stretching and bending frequencies in methanol. J Chem Phys 2000. [DOI: 10.1063/1.1288372] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Lees RM, Xu LH. Dark state illuminated: infrared spectrum and inverted torsional structure of the nu(11) out-of-plane CH3-rocking mode of methanol. PHYSICAL REVIEW LETTERS 2000; 84:3815-3818. [PMID: 11019213 DOI: 10.1103/physrevlett.84.3815] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/1999] [Indexed: 05/23/2023]
Abstract
The nu(11) out-of-plane CH3-rocking band of methanol, one of the last fundamentals remaining en route to full vibrational description of this prototype internal rotor, has been identified in the Fourier transform spectrum of CH3OH in the 1150 cm(-1) region. The nu(11) torsional energy pattern is found to be inverted, the first such discovery for a bending state and an important pointer to potential generality of this phenomenon for the whole class of threefold internal rotor molecules. Level-crossing resonances giving transfer channels for intramolecular vibrational energy redistribution (IVR) have been found, and new insights are reported for far-infrared laser emission involving nu(11) levels.
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Affiliation(s)
- RM Lees
- Department of Physics, University of New Brunswick, Fredericton, New Brunswick, Canada E3B 5A3
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Buchhold K, Reimann B, Djafari S, Barth HD, Brutschy B, Tarakeshwar P, Kim KS. Fluorobenzene and p-difluorobenzene microsolvated by methanol: An infrared spectroscopic and ab initio theoretical investigation. J Chem Phys 2000. [DOI: 10.1063/1.480748] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Hänninen V, Horn M, Halonen L. Torsional motion and vibrational overtone spectroscopy of methanol. J Chem Phys 1999. [DOI: 10.1063/1.479583] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Boyarkin OV, Rizzo TR, Perry DS. Intramolecular energy transfer in highly vibrationally excited methanol. III. Rotational and torsional analysis. J Chem Phys 1999. [DOI: 10.1063/1.479076] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Wang X, Perry DS. An internal coordinate model of coupling between the torsion and C–H vibrations in methanol. J Chem Phys 1998. [DOI: 10.1063/1.477777] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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