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Suárez E, Guzmán-Juárez O, Lemus R. Novel Criteria to Provide a Locality/Normality Degree in Molecules and Their Relevance in Physical Chemistry. Molecules 2024; 29:3490. [PMID: 39124895 PMCID: PMC11314194 DOI: 10.3390/molecules29153490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2024] [Revised: 07/18/2024] [Accepted: 07/19/2024] [Indexed: 08/12/2024] Open
Abstract
In contrast to the traditional analysis of molecules using local mode behavior, where the degree of locality is given through a function in terms of Morse potential parameters, new criteria for locality/normality (LN) suitable for application to any molecular system are proposed. The approach is based on analysis of the connection between the algebraic normal and local mode representations. It is shown that both descriptions are equivalent as long as the polyad (total number of quanta) in the local representation is not conserved. The constraint of a local polyad conservation naturally provides a criterion for assigning an LN degree in quantitative form, without an analogue in configuration space. The correlation between the different parameters reveals the physical properties of molecules. A clear connection between the LN degree (based on the fundamentals) and spectroscopic properties is also presented, suggesting a promising approach for identifying mixtures of isotopologues.
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Affiliation(s)
| | | | - Renato Lemus
- Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, A.P. 70-543, Circuito Exterior, C. U., Mexico City 04510, Mexico; (E.S.); (O.G.-J.)
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2
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Maurer M, Lazaridis T. Comparison of classical and ab initio simulations of hydronium and aqueous proton transfer. J Chem Phys 2023; 159:134506. [PMID: 37795787 DOI: 10.1063/5.0166596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 09/25/2023] [Indexed: 10/06/2023] Open
Abstract
Proton transport in aqueous systems occurs by making and breaking covalent bonds, a process that classical force fields cannot reproduce. Various attempts have been made to remedy this deficiency, by valence bond theory or instantaneous proton transfers, but the ability of such methods to provide a realistic picture of this fundamental process has not been fully evaluated. Here we compare an ab initio molecular dynamics (AIMD) simulation of an excess proton in water to a simulation of a classical H3O+ in TIP3P water. The energy gap upon instantaneous proton transfer from H3O+ to an acceptor water molecule is much higher in the classical simulation than in the AIMD configurations evaluated with the same classical potential. The origins of this discrepancy are identified by comparing the solvent structures around the excess proton in the two systems. One major structural difference is in the tilt angle of the water molecules that accept an hydrogen bond from H3O+. The lack of lone pairs in TIP3P produces a tilt angle that is too large and generates an unfavorable geometry after instantaneous proton transfer. This problem can be alleviated by the use of TIP5P, which gives a tilt angle much closer to the AIMD result. Another important factor that raises the energy gap is the different optimal distance in water-water vs H3O+-water H-bonds. In AIMD the acceptor is gradually polarized and takes a hydronium-like configuration even before proton transfer actually happens. Ways to remedy some of these problems in classical simulations are discussed.
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Affiliation(s)
- Manuela Maurer
- Department of Chemistry, City College of New York/CUNY, 160 Convent Ave., New York, New York 10031, USA
| | - Themis Lazaridis
- Department of Chemistry, City College of New York/CUNY, 160 Convent Ave., New York, New York 10031, USA
- Graduate Programs in Chemistry, Biochemistry, and Physics, The Graduate Center, City University of New York, 365 Fifth Ave., New York, New York 10016, USA
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3
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Pitsevich GA, Malevich AE, Kamnev AA. A convenient set of vibrational coordinates for 2D calculation of the tunneling splittings of the ground state and some excited vibrational states for the inversion motion in H 3O +, H 3O -, and H 3O. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 296:122660. [PMID: 37043918 DOI: 10.1016/j.saa.2023.122660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 03/10/2023] [Accepted: 03/19/2023] [Indexed: 06/19/2023]
Abstract
Splitting of the ground state and some excited symmetric bending vibrational states due to inversion tunneling of the oxygen atom in the H3O+, H3O- ions and in the H3O radical are analyzed by numerically solving the vibrational Schrödinger equation of restricted (2D) dimensionality. As two vibrational coordinates, we used 1) the distance of the oxygen atom from the plane of a regular triangle formed by three hydrogen atoms and 2) a symmetry coordinate composed of three distances between chemically non-bonded hydrogen atoms. The kinetic energy operator in this case takes the simplest form. The 2D potential energy surface (PES) in the given coordinates was calculated for H3O+ at the CCSD(T)/aug-cc-pVTZ and CCSD(T)-F12/cc-pVTZ-F12 levels of theory. The same 2D PES for the H3O- anion and H3O radical were calculated at the CCSD(T)/aug-cc-pVQZ, CCSD(T)/d-aug-cc-pVQZ and UCCSD(T)/aug-cc-pVQZ, UCCSD(T)/d-aug-cc-pVQZ levels of theory, respectively. The tunneling splittings were calculated for the cations H316O+, D316O+, T316O+, H318O+, D318O+, T318O+. The tunneling splittings for the H3O-, D3O-, T3O- anions and H3O, D3O, T3O radicals were calculated for the first time. The results of calculations demonstrate good agreement with experimental values of the tunneling splittings in the ground state and in some excited vibrational states of the H316O+ and D316O+ cations.
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Affiliation(s)
- George A Pitsevich
- Department of Physical Optics and Applied Informatics, Faculty of Physics, Belarusian State University, Nezavisimosti Ave., 4, 220030 Minsk, Belarus.
| | - Alex E Malevich
- Department of Differential Equations and System Analysis, Faculty of Mechanics and Mathematics, Belarusian State University, Nezavisimosti Ave., 4, 220030 Minsk, Belarus
| | - Alexander A Kamnev
- Laboratory of Biochemistry, Institute of Biochemistry and Physiology of Plants and Microorganisms - Subdivision of the Federal State Budgetary Research Institution Saratov Federal Scientific Center of the Russian Academy of Sciences, Prosp. Entuziastov, 13, 410049 Saratov, Russia.
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4
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Bhattacharyya D, Ramesh SG. Wavepacket dynamical study of H-atom tunneling in catecholate monoanion: the role of intermode couplings and energy flow. Phys Chem Chem Phys 2023; 25:1923-1936. [PMID: 36541267 DOI: 10.1039/d2cp03803j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We present a study of H-atom tunneling in catecholate monoanion through wavepacket dynamical simulations. In our earlier study of this symmetrical double-well system [Phys. Chem. Chem. Phys., 2022, 24, 10887], a limited number of transition state modes were identified as being important for the tunneling process. These include the imaginary frequency mode Q1, the CO scissor mode Q10, and the OHO bending mode Q29. In this work, starting from non-stationary initial states prepared with excitations in these modes, we have carried out wavepacket dynamics in two and three dimensional spaces. We analyse the dynamical effects of the intermode couplings, in particular the role of energy flow between the studied modes on H-atom tunneling. We find that while Q10 strongly modulates the donor-acceptor distance, it does not exchange energy with Q1. However, excitation in Q29 or Q1 does lead to rapid energy exchange between these modes, which modifies the tunneling rate at early times.
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Affiliation(s)
- Debabrata Bhattacharyya
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore, 560012, India.
| | - Sai G Ramesh
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore, 560012, India.
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5
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Lazaridis T. Molecular origins of asymmetric proton conduction in the influenza M2 channel. Biophys J 2023; 122:90-98. [PMID: 36403086 PMCID: PMC9822799 DOI: 10.1016/j.bpj.2022.11.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/13/2022] [Accepted: 11/17/2022] [Indexed: 11/20/2022] Open
Abstract
The M2 proton channel of influenza A is embedded into the viral envelope and allows acidification of the virion when the external pH is lowered. In contrast, no outward proton conductance is observed when the internal pH is lowered, although outward current is observed at positive voltage. Residues Trp41 and Asp44 are known to play a role in preventing pH-driven outward conductance, but the mechanism for this is unclear. We investigate this issue using classical molecular dynamics simulations with periodic proton hops. When all key His37 residues are neutral, inward proton movement is much more facile than outward movement if the His are allowed to shuttle the proton. The preference for inward movement increases further as the charge on the His37 increases. Analysis of the trajectories reveals three factors accounting for this asymmetry. First, in the outward direction, Asp44 traps the hydronium by strong electrostatic interactions. Secondly, Asp44 and Trp41 orient the hydronium with the protons pointing inward, hampering outward Grotthus hopping. As a result, the effective barrier is lower in the inward direction. Trp41 adds to the barrier by weakly H-bonding to potential H+ acceptors. Finally, for charged His, the H3O+ in the inner vestibule tends to get trapped at lipid-lined fenestrations of the cone-shaped channel. Simulations qualitatively reproduce the experimentally observed higher outward conductance of mutants. The ability of positive voltage, unlike proton gradient, to induce an outward current appears to arise from its ability to bias H3O+ and the waters around it toward more H-outward orientations.
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Affiliation(s)
- Themis Lazaridis
- Department of Chemistry, City College of New York/CUNY, New York, New York; Graduate Programs in Chemistry, Biochemistry, and Physics, The Graduate Center, City University of New York, New York, New York.
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6
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Puzzarini C, Bloino J, Tasinato N, Barone V. Accuracy and Interpretability: The Devil and the Holy Grail. New Routes across Old Boundaries in Computational Spectroscopy. Chem Rev 2019; 119:8131-8191. [DOI: 10.1021/acs.chemrev.9b00007] [Citation(s) in RCA: 114] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Cristina Puzzarini
- Dipartimento di Chimica “Giacomo Ciamician”, Università di Bologna, Via F. Selmi 2, I-40126 Bologna, Italy
| | - Julien Bloino
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
| | - Nicola Tasinato
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
| | - Vincenzo Barone
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
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7
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Meisner J, Hallmen PP, Kästner J, Rauhut G. Vibrational analysis of methyl cation—Rare gas atom complexes: CH3+—Rg (Rg = He, Ne, Ar, Kr). J Chem Phys 2019; 150:084306. [DOI: 10.1063/1.5084100] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Jan Meisner
- Institute for Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, USA
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Philipp P. Hallmen
- Institute for Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Johannes Kästner
- Institute for Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Guntram Rauhut
- Institute for Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
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8
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Duong CH, Yang N, Kelleher PJ, Johnson MA, DiRisio RJ, McCoy AB, Yu Q, Bowman JM, Henderson BV, Jordan KD. Tag-Free and Isotopomer-Selective Vibrational Spectroscopy of the Cryogenically Cooled H9O4+ Cation with Two-Color, IR–IR Double-Resonance Photoexcitation: Isolating the Spectral Signature of a Single OH Group in the Hydronium Ion Core. J Phys Chem A 2018; 122:9275-9284. [DOI: 10.1021/acs.jpca.8b08507] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Chinh H. Duong
- Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut 06520, United States
| | - Nan Yang
- Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut 06520, United States
| | - Patrick J. Kelleher
- Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut 06520, United States
| | - Mark A. Johnson
- Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut 06520, United States
| | - Ryan J. DiRisio
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Anne B. McCoy
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Qi Yu
- Department of Chemistry and Cherry L. Emerson Center for Computational Science, Emory University, Atlanta, Georgia 30322, United States
| | - Joel M. Bowman
- Department of Chemistry and Cherry L. Emerson Center for Computational Science, Emory University, Atlanta, Georgia 30322, United States
| | - Bryan V. Henderson
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Kenneth D. Jordan
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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9
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Bowman MC, Zhang B, James Morgan W, Schaefer HF. A remarkable case of basis set dependence: the false convergence patterns of the methyl anion. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1478139] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- Michael C. Bowman
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia
| | - Boyi Zhang
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia
| | - W. James Morgan
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia
| | - Henry F. Schaefer
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia
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10
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Yu Q, Bowman JM. How the Zundel (H 5O 2+) Potential Can Be Used to Predict the Proton Stretch and Bend Frequencies of Larger Protonated Water Clusters. J Phys Chem Lett 2016; 7:5259-5265. [PMID: 27973907 DOI: 10.1021/acs.jpclett.6b02561] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
From a series of seminal experiments on the IR spectra of protonated water clusters and associated theoretical analyses, it is clear that the energies and spectral features of the proton stretch and bend modes are very sensitive functions of the cluster size. Here we show that this dynamic range can be understood by examining the sensitivity of these modes in the potential of the Zundel cation, H5O2+, as the separation of the two water monomers is varied. As this distance increases, the proton increasingly localizes on a monomer, and this is encoded in the IR spectrum of the proton vibrational modes. The quantitative predictions from this simple correlation are verified for the H7O3+ and H9O4+ clusters, for which new benchmark harmonic frequencies are reported. The predictions are also in good accord with trends seen experimentally and previous calculations for these and five other clusters, including H+(H2O)21.
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Affiliation(s)
- Qi Yu
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University , Atlanta, Georgia 30322, United States
| | - Joel M Bowman
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University , Atlanta, Georgia 30322, United States
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11
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Yu Q, Bowman JM. Ab Initio Potential for H3O+ → H+ + H2O: A Step to a Many-Body Representation of the Hydrated Proton? J Chem Theory Comput 2016; 12:5284-5292. [DOI: 10.1021/acs.jctc.6b00765] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Qi Yu
- Department of Chemistry and
Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, United States
| | - Joel M. Bowman
- Department of Chemistry and
Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, United States
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12
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Oliveira AM, Lu YJ, Lehman JH, Changala PB, Baraban JH, Stanton JF, Lineberger WC. Photoelectron Spectroscopy of the Methide Anion: Electron Affinities of •CH3 and •CD3 and Inversion Splittings of CH3– and CD3–. J Am Chem Soc 2015; 137:12939-45. [PMID: 26389796 DOI: 10.1021/jacs.5b07013] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | | | - Joshua H. Baraban
- Department
of Chemistry, University of Texas, Austin, Texas 78712, United States
| | - John F. Stanton
- Department
of Chemistry, University of Texas, Austin, Texas 78712, United States
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13
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Isotope effects of ammonia umbrella flip using semiclassical instanton calculations based on discretized path integrals. Chem Phys Lett 2015. [DOI: 10.1016/j.cplett.2015.05.072] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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14
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Li A, Guo H. A Full-Dimensional Global Potential Energy Surface of H3O+(ã3A) for the OH+(X̃3Σ–) + H2(X̃1Σg+) → H(2S) + H2O+(X̃2B1) Reaction. J Phys Chem A 2014; 118:11168-76. [DOI: 10.1021/jp5100507] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Anyang Li
- Department of Chemistry
and
Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Hua Guo
- Department of Chemistry
and
Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, United States
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15
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Kawatsu T, Miura S. Efficient algorithms for semiclassical instanton calculations based on discretized path integrals. J Chem Phys 2014; 141:024101. [DOI: 10.1063/1.4885437] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
- Tsutomu Kawatsu
- Institute for Molecular Science, National Institute of Natural Science, 38 Nishigonaka, Myodaiji, Okazaki 222-8585, Japan
- School of Mathematics and Physics, Kanazawa University, Kanazawa 920-1192, Japan
| | - Shinichi Miura
- School of Mathematics and Physics, Kanazawa University, Kanazawa 920-1192, Japan
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Neff M, Rauhut G. Towards black-box calculations of tunneling splittings obtained from vibrational structure methods based on normal coordinates. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2014; 119:100-106. [PMID: 23548204 DOI: 10.1016/j.saa.2013.02.033] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 02/14/2013] [Accepted: 02/18/2013] [Indexed: 06/02/2023]
Abstract
Multidimensional potential energy surfaces obtained from explicitly correlated coupled-cluster calculations and further corrections for high-order correlation contributions, scalar relativistic effects and core-correlation energy contributions were generated in a fully automated fashion for the double-minimum benchmark systems OH3(+) and NH3. The black-box generation of the potentials is based on normal coordinates, which were used in the underlying multimode expansions of the potentials and the μ-tensor within the Watson operator. Normal coordinates are not the optimal choice for describing double-minimum potentials and the question remains if they can be used for accurate calculations at all. However, their unique definition is an appealing feature, which removes remaining errors in truncated potential expansions arising from different choices of curvilinear coordinate systems. Fully automated calculations are presented, which demonstrate, that the proposed scheme allows for the determination of energy levels and tunneling splittings as a routine application.
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Affiliation(s)
- Michael Neff
- Institute of Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
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Abstract
Dissociative photoionization onsets of water and water dimer, measured by Imaging Photoelectron Photoion Coincidence (iPEPICO) Spectroscopy, are used in a floating thermochemical cycle to determine the proton affinity of water with unprecedented accuracy, as confirmed by state-of-the-artab initioquantum-chemical calculations.
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Affiliation(s)
- A. Bodi
- Molecular Dynamics Group
- Paul Scherrer Institut
- Villigen 5232, Switzerland
| | - J. Csontos
- MTA-BME Lendület Quantum Chemistry Research Group
- Department of Physical Chemistry and Materials Science
- Budapest University of Technology and Economics
- Budapest 1521, Hungary
| | - M. Kállay
- MTA-BME Lendület Quantum Chemistry Research Group
- Department of Physical Chemistry and Materials Science
- Budapest University of Technology and Economics
- Budapest 1521, Hungary
| | - S. Borkar
- Department of Chemistry
- University of the Pacific
- Stockton, USA
| | - B. Sztáray
- Department of Chemistry
- University of the Pacific
- Stockton, USA
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18
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Petit AS, Ford JE, McCoy AB. Simultaneous Evaluation of Multiple Rotationally Excited States of H3+, H3O+, and CH5+ Using Diffusion Monte Carlo. J Phys Chem A 2013; 118:7206-20. [DOI: 10.1021/jp408821a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Andrew S. Petit
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Jason E. Ford
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Anne B. McCoy
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
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19
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Pfeiffer F, Rauhut G, Feller D, Peterson KA. Anharmonic zero point vibrational energies: Tipping the scales in accurate thermochemistry calculations? J Chem Phys 2013; 138:044311. [DOI: 10.1063/1.4777568] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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20
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Szabó I, Fábri C, Czakó G, Mátyus E, Császár AG. Temperature-Dependent, Effective Structures of the 14NH3 and 14ND3 Molecules. J Phys Chem A 2012; 116:4356-62. [DOI: 10.1021/jp211802y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- István Szabó
- Laboratory of Molecular
Structure and Dynamics, Institute of Chemistry, Eötvös University, H-1518 Budapest 112, P.O. Box 32, Hungary
| | - Csaba Fábri
- Laboratory of Molecular
Structure and Dynamics, Institute of Chemistry, Eötvös University, H-1518 Budapest 112, P.O. Box 32, Hungary
| | - Gábor Czakó
- Laboratory of Molecular
Structure and Dynamics, Institute of Chemistry, Eötvös University, H-1518 Budapest 112, P.O. Box 32, Hungary
| | - Edit Mátyus
- Laboratory of Molecular
Structure and Dynamics, Institute of Chemistry, Eötvös University, H-1518 Budapest 112, P.O. Box 32, Hungary
| | - Attila G. Császár
- Laboratory of Molecular
Structure and Dynamics, Institute of Chemistry, Eötvös University, H-1518 Budapest 112, P.O. Box 32, Hungary
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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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Yachmenev A, Yurchenko SN, Ribeyre T, Thiel W. High-level ab initio potential energy surfaces and vibrational energies of H2CS. J Chem Phys 2011; 135:074302. [DOI: 10.1063/1.3624570] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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23
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Abstract
Hildenbrand and co-workers have shown recently that the vapor above solid ammonium nitrate includes molecules of NH₄NO₃, not only NH₃ and HNO₃ as previously believed. Their measurements led to thermochemical values that imply an enthalpy change of D₂₉₈ = 98 ± 9 kJ mol⁻¹ for the gas-phase dissociation of ammonium nitrate into NH₃ and HNO₃. Using updated spectroscopic information for the partition function leads to the revised value of D₂₉₈ = 78 ± 21 kJ mol⁻¹ (accompanying paper in this journal, Hildenbrand, D. L., Lau, K. H., and Chandra, D. J. Phys. Chem. B 2010, DOI: 10.1021/jp105773q). In contrast, high-level ab initio calculations, detailed in the present report, predict a dissociation enthalpy half as large as the original result, 50 ± 3 kJ mol⁻¹. These are frozen-core CCSD(T) calculations extrapolated to the limiting basis set aug-cc-pV∞Z using an anharmonic vibrational partition function and a variational treatment of the NH₃ rotor. The corresponding enthalpy of formation is Δ(f)H₂₉₈°(NH₄NO₃,g) = −230.6 ± 3 kJ mol⁻¹. The origin of the disagreement with experiment remains unexplained.
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Affiliation(s)
- Karl K Irikura
- Chemical and Biochemical Reference Data Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8320, USA
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24
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Carter S, Handy NC, Bowman JM. High torsional vibrational energies of H2O2 and CH3OH studied by MULTIMODE with a large amplitude motion coupled to two effective contraction schemes. Mol Phys 2010. [DOI: 10.1080/00268970802467986] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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25
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26
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Müller HSP, Dong F, Nesbitt DJ, Furuya T, Saito S. Tunneling dynamics and spectroscopic parameters of monodeuterated hydronium, H(2)DO(+), from a combined analysis of infrared and sub-millimeter spectra. Phys Chem Chem Phys 2010; 12:8362-72. [PMID: 20505867 DOI: 10.1039/c002067b] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The infrared laser direct absorption spectrum of H(2)DO(+) in the OH stretching region was reported quite recently revealing large amplitude tunneling dynamics. The large rotational constants make the jet-cooled spectrum relatively sparse at low rotational temperatures and assignments thus challenging. Transitions were assigned through ground state combination differences, with additional tentative assignments made via comparison of predicted/observed spectra. More recently, 9 rotation-inversion transitions were recorded in the sub-millimeter (sub-mm) region, which yielded tunneling splittings and rotational constants differing slightly from IR results. This has prompted the present reinvestigation of the H(2)DO(+) spectra, which now takes full advantage of the combined data from both studies. While previous analyses considered each tunneling state as independent and non-interacting, the present analysis is based on a tunneling-Hamiltonian model for the well studied, isoelectronic NH(2)D molecule, modified to account for the larger tunneling splitting. The combined analysis revealed rotational interaction between tunneling states as well as between the two OH stretching modes and permitted a substantial number of new assignments to be made, including one sub-millimeter transition while only few IR assignments had to be corrected or omitted. It leads to improvement in parameters for both the ground as well as for the OH stretching states of this important molecular ion, which reproduce the assigned lines within experimental uncertainties, provides guidance, e.g., for the spectral search in the OD stretch region, and yields deeper insight into the tunneling dynamics.
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Affiliation(s)
- Holger S P Müller
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany.
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27
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Ragni M, Lombardi A, Barreto PRP, Bitencourt ACP. Orthogonal coordinates and hyperquantization algorithm. The NH3 and H3O+ umbrella inversion levels. J Phys Chem A 2009; 113:15355-65. [PMID: 19757778 DOI: 10.1021/jp906415m] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In order to describe the umbrella inversion mode, which is characteristic of AB(3)-type molecules, we have introduced an alternative hyperspherical coordinate set based on a parametrization of Radau-Smith orthogonal vectors and have considered constraints which allow us to enforce the C(3v) symmetry. Structural properties and electronic energies at equilibrium and barrier configurations have been obtained at MP2 and CCSD(T) levels of theory. Energy profiles have been calculated using the CCSD(T) method with an aug-cc-pVQZ basis set. The NH(3) and H(3)O(+) umbrella inversion levels are obtained by the hyperquantization algorithm for a one-dimensional calculation, using a specially defined hyperangle as the inversion coordinate. The results are compared with experimental and theoretical energy levels, in particular, with those obtained by calculations based on two-dimensional models. The emerging picture of the umbrella inversion based on this hyperangular coordinate compares favorably with respect to the usual valence-type description.
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Affiliation(s)
- M Ragni
- Dipartimento di Chimica, Universitá di Perugia, 06123 Perugia, Italy
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28
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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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29
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Xie Z, Bowman JM. Permutationally Invariant Polynomial Basis for Molecular Energy Surface Fitting via Monomial Symmetrization. J Chem Theory Comput 2009; 6:26-34. [DOI: 10.1021/ct9004917] [Citation(s) in RCA: 202] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Zhen Xie
- Mathematics and Computer Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439 and Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, 1515 Dickey Drive, Emory University, Atlanta, Georgia 30322
| | - Joel M. Bowman
- Mathematics and Computer Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439 and Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, 1515 Dickey Drive, Emory University, Atlanta, Georgia 30322
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30
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Petit AS, McCoy AB. Diffusion Monte Carlo Approaches for Evaluating Rotationally Excited States of Symmetric Top Molecules: Application to H3O+ and D3O+. J Phys Chem A 2009; 113:12706-14. [DOI: 10.1021/jp905098k] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Andrew S. Petit
- Department of Chemistry, The Ohio State University, Columbus, Ohio 43210
| | - Anne B. McCoy
- Department of Chemistry, The Ohio State University, Columbus, Ohio 43210
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31
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Yurchenko SN, Barber RJ, Yachmenev A, Thiel W, Jensen P, Tennyson J. A Variationally Computed T = 300 K Line List for NH3. J Phys Chem A 2009; 113:11845-55. [DOI: 10.1021/jp9029425] [Citation(s) in RCA: 152] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sergei N. Yurchenko
- Institut für Physikalische Chemie und Elektrochemie, Technische Universität Dresden, D-01062 Dresden, Germany, Department of Physics and Astronomy, University College London, London WC1E 6BT, U.K., Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany, and FBC, Theoretische Chemie, Bergische Universität, D-42097 Wuppertal, Germany
| | - Robert J. Barber
- Institut für Physikalische Chemie und Elektrochemie, Technische Universität Dresden, D-01062 Dresden, Germany, Department of Physics and Astronomy, University College London, London WC1E 6BT, U.K., Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany, and FBC, Theoretische Chemie, Bergische Universität, D-42097 Wuppertal, Germany
| | - Andrey Yachmenev
- Institut für Physikalische Chemie und Elektrochemie, Technische Universität Dresden, D-01062 Dresden, Germany, Department of Physics and Astronomy, University College London, London WC1E 6BT, U.K., Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany, and FBC, Theoretische Chemie, Bergische Universität, D-42097 Wuppertal, Germany
| | - Walter Thiel
- Institut für Physikalische Chemie und Elektrochemie, Technische Universität Dresden, D-01062 Dresden, Germany, Department of Physics and Astronomy, University College London, London WC1E 6BT, U.K., Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany, and FBC, Theoretische Chemie, Bergische Universität, D-42097 Wuppertal, Germany
| | - Per Jensen
- Institut für Physikalische Chemie und Elektrochemie, Technische Universität Dresden, D-01062 Dresden, Germany, Department of Physics and Astronomy, University College London, London WC1E 6BT, U.K., Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany, and FBC, Theoretische Chemie, Bergische Universität, D-42097 Wuppertal, Germany
| | - Jonathan Tennyson
- Institut für Physikalische Chemie und Elektrochemie, Technische Universität Dresden, D-01062 Dresden, Germany, Department of Physics and Astronomy, University College London, London WC1E 6BT, U.K., Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany, and FBC, Theoretische Chemie, Bergische Universität, D-42097 Wuppertal, Germany
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32
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Luis JM, Reis H, Papadopoulos M, Kirtman B. Treatment of nonlinear optical properties due to large amplitude anharmonic vibrational motions: Umbrella motion in NH3. J Chem Phys 2009; 131:034116. [PMID: 19624190 DOI: 10.1063/1.3171615] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Josep M Luis
- Department of Chemistry and Institute of Computational Chemistry, University of Girona, Campus de Montilivi, 17071 Girona, Catalonia, Spain.
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33
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An experimental and theoretical description of the (NH3)−1{NH3–H–H2O}+ cluster ions produced by fast ion bombardment. Chem Phys Lett 2009. [DOI: 10.1016/j.cplett.2009.04.054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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34
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Furuya T, Saito S. Microwave spectrum of the HD2O+ ion: inversion-rotation transitions and inversion splitting. J Chem Phys 2008; 128:034311. [PMID: 18205502 DOI: 10.1063/1.2822284] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Inversion-rotation spectral lines of the dideuterated hydronium ion, HD2O+, have been observed by a source-modulation millimeter- to submillimeter-wave spectrometer. The ion was generated by a hollow-cathode discharge in a gas mixture of D2O and H2O in a free-space cell. Ten inversion-rotation lines were measured precisely for the lowest pair of inversion doublets in the frequency region from 380 to 730 GHz. The observed lines include the most astronomically important transitions, 0(00) (-)-1(10)+ for the para species at 380 538.031(32) MHz and 1(01) (-)-1(11)+ for the ortho species at 728 420.189(34) MHz, which could be used as a radio astronomical probe investigating interstellar chemistry of deuterium fractionation. An analysis of the measured lines has yielded the rotational constants in the ground doublet states and the inversion splitting. The inversion splitting in the ground state was determined to be 808 866(34) MHz, that is, 26.980 87(113) cm(-1), where the numbers in parentheses give uncertainties estimated from the Jacobian matrix of the assumed centrifugal distortion constants. The determined inversion splitting is off by -0.51 cm(-1) from the predicted value of 27.49 cm(-1) by Rajamaki et al. using high-order coupled cluster ab initio calculation [J. Chem. Phys. 118, 10929 (2003)], and by -0.0510 cm(-1) from the observed value of 27.0318(72) cm(-1) by Dong et al. using high-resolution jet-cooled infrared spectroscopy [J. Chem. Phys. 122, 224301 (2005)] beyond the quoted uncertainty.
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Affiliation(s)
- Takashi Furuya
- Research Center for Development of Far-Infrared Region, University of Fukui, Bunkyo, Fukui 910-8507, Japan
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35
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Nesbitt DJ, Dong F. Ab initio large-amplitude quantum-tunneling dynamics in vinyl radical: a vibrationally adiabatic approach. Phys Chem Chem Phys 2008; 10:2113-22. [DOI: 10.1039/b800880a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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36
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Furuya T, Saito S, Araki M. Microwave spectrum of the H2DO+ ion: inversion-rotation transitions and inversion splitting. J Chem Phys 2007; 127:244314. [PMID: 18163682 DOI: 10.1063/1.2813352] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Inversion-rotation spectral lines of the monodeuterated hydronium ion, H(2)DO(+), have been observed by a source-modulation spectrometer in the millimeter- to submillimeter-wave region. The ion was generated by a hollow-cathode discharge in a gas mixture of H(2)O and D(2)O. Nine inversion-rotation lines were measured precisely for the lowest pair of inversion doublets in the frequency region from 210 to 720 GHz. The measured lines were analyzed to derive rotational constants in the inversion-doublet states and inversion splitting. The inversion splitting in the ground state was determined to be 1,215,866(410) MHz, that is, 40.5569(137) cm(-1), where the numbers in parentheses give probable uncertainties estimated from the Jacobian matrix of the assumed centrifugal distortion constants of the inversion-doublet states. The determined inversion splitting is off by -0.58 cm(-1) from the predicted value of 41.14 cm(-1) by Rayamaki et al. using high-order coupled cluster ab initio calculations [J. Chem. Phys. 118, 10929 (2003)], and by 0.039 cm(-1) from the observed value of 40.518(10) cm(-1) by Dong and Nesbitt using high-resolution jet-cooled infrared spectroscopy [J. Chem. Phys. 125, 144311 (2006)] beyond the quoted uncertainty. The most astronomically important transition 0(00)(-)-1(0)(+) for the ortho species was measured at 673,257.024(31) MHz, which could be used as a radioastronomical probe investigating interstellar chemistry of deuterium fractionation in space.
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Affiliation(s)
- Takashi Furuya
- Research Center for Development of Far-Infrared Region, University of Fukui, Bunkyo, Fukui 910-8507, Japan
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37
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Viel A, Eisfeld W, Neumann S, Domcke W, Manthe U. Photoionization-induced dynamics of ammonia: ab initio potential energy surfaces and time-dependent wave packet calculations for the ammonia cation. J Chem Phys 2007; 124:214306. [PMID: 16774406 DOI: 10.1063/1.2202316] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
An analytical anharmonic six-dimensional three-sheeted potential energy surface for the ground and first excited states of the ammonia cation has been developed which is tailored to model the ultrafast photoinduced dynamics. Selected ab initio cuts, obtained by multireference configuration interaction calculations, have been used to determine the parameters of a diabatic representation for this Jahn-Teller and pseudo-Jahn-Teller system. The model includes higher-order coupling terms both for the Jahn-Teller and for the pseudo-Jahn-Teller matrix elements. The relaxation to the ground state is possible via dynamical pseudo-Jahn-Teller couplings involving the asymmetric bending and stretching coordinates. The photoelectron spectrum of NH3 and the internal conversion dynamics of NH3+ have been determined by wave packet propagation calculations employing the multiconfigurational time-dependent Hartree method. Three different time scales are found in the dynamics calculations for the second absorption band. The ultrafast Jahn-Teller dynamics of the two excited states occurs on a 5 fs time scale. The major part of the internal conversion to the ground state takes place within a short time scale of 20 fs. This fast internal conversion is, however, incomplete and the remaining excited state population does not decay completely even within 100 fs.
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Affiliation(s)
- Alexandra Viel
- Laboratoire de Physique des Atomes, Lasers, Molécules et Surfaces (PALMS), CNRS UMR 6627, Université de Rennes 1, Campus de Beaulieu, F-35042 Rennes, France.
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38
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Miani A, Raugei S, Carloni P, Helfand MS. Structure and Raman Spectrum of Clavulanic Acid in Aqueous Solution. J Phys Chem B 2007; 111:2621-30. [PMID: 17302447 DOI: 10.1021/jp066135u] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The calculation of the vibrational Raman spectrum of enzyme-bound beta-lactamase inhibitors may be of help to understand the mechanisms responsible for bacterial drug resistance. Here, we present a study of the solvation structure and the vibrational properties of clavulanate, an important beta-lactamase inhibitor, in aqueous solution as obtained from full quantum and hybrid empirical/quantum molecular dynamics simulations at ambient conditions. The analysis of the vibrational density of states indicates that hybrid empirical/quantum mechanical simulations are able to properly describe the vibrational levels of clavulanate in solution. In addition, we propose a computationally efficient protocol to calculate the vibrational Raman effect for large solute molecules in water, which is able to faithfully reproduce the experimentally recorded clavulanate Raman spectrum and discloses the possibility to employ hybrid simulations to assign the experimental Raman spectra of inhibitors bound to beta-lactamases.
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Affiliation(s)
- Andrea Miani
- SISSA/ISAS and INFM-DEMOCRITOS, Modeling Center for Research in Atomistic Simulation, via Beirut 2, I-34014, Trieste, Italy
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39
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Dong F, Nesbitt DJ. Jet cooled spectroscopy of H2DO+: Barrier heights and isotope-dependent tunneling dynamics from H3O+ to D3O+. J Chem Phys 2006; 125:144311. [PMID: 17042594 DOI: 10.1063/1.2338520] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The first high resolution spectroscopic data for jet cooled H2DO+ are reported, specifically via infrared laser direct absorption in the OH stretching region with a slit supersonic jet discharge source. Transitions sampling upper (0-) and lower (0+) tunneling states for both symmetric (nu1+ <-- 0+, nu1- <-- 0-, and nu1- <-- 0+) and antisymmetric (nu3+ <-- 0+ and nu3- <-- 0-) OH stretching bands are observed, where +/- refers to wave function reflection symmetry with respect to the planar umbrella mode transition state. The spectra can be well fitted to a Watson asymmetric top Hamiltonian, revealing band origins and rotational constants for benchmark comparison with high-level ab initio theory. Of particular importance are detection and assignment of the relatively weak band (nu1- <-- 0+) that crosses the inversion tunneling gap, which is optically forbidden in H3O+ or D3O+, but weakly allowed in H2DO+ by lowering of the tunneling transition state symmetry from D(3h) to C(2v). In conjunction with other H2DO+ bands, this permits determination of the tunneling splittings to within spectroscopic precision for each of the ground [40.518(10) cm(-1)], nu1 = 1 [32.666(6) cm(-1)], and nu3 = 1 [25.399(11) cm(-1)] states. A one-dimensional zero-point energy corrected potential along the tunneling coordinate is constructed from high-level ab initio CCSD(T) calculations (AVnZ, n = 3,4,5) and extrapolated to the complete basis set limit to extract tunneling splittings via a vibrationally adiabatic treatment. Perturbative scaling of the potential to match splittings for all four isotopomers permits an experimental estimate of DeltaV0 = 652.9(6) cm(-1) for the tunneling barrier, in good agreement with full six-dimensional ab initio results of Rajamaki, Miani, and Halonen (RMH) [J. Chem. Phys. 118, 10929 (2003)]. (DeltaV0 (RMH) = 650 cm(-1)). The 30%-50% decrease in tunneling splitting observed upon nu1 and nu3 vibrational excitations arises from an increase in OH stretch frequencies at the planar transition state, highlighting the transition between sp2 and sp3 hybridizations of the OHD bonds as a function of inversion bending angle.
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Affiliation(s)
- Feng Dong
- JILA, National Institute of Standards and Technology, University of Colorado, Boulder, Colorado 80309, USA
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40
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Yang J, Li J, Hao Y, Zhou C, Mo Y. Inversion vibration of PH3+(X2A2") studied by zero kinetic energy photoelectron spectroscopy. J Chem Phys 2006; 125:054311. [PMID: 16942217 DOI: 10.1063/1.2229211] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report the first rotationally resolved spectroscopic studies on PH3+(X2A2") using zero kinetic energy photoelectron spectroscopy and coherent VUV radiation. The spectra about 8000 cm(-1) above the ground vibrational state of PH3+(X2A2") have been recorded. We observed the vibrational energy level splittings of PH3+(X2A2") due to the tunneling effect in the inversion (symmetric bending) vibration (nu2+). The energy splitting for the first inversion vibrational state (0+/0-) is 5.8 cm(-1). The inversion vibrational energy levels, rotational constants, and adiabatic ionization energies (IEs) for nu2+ = 0-16 have been determined. The bond angles between the neighboring P-H bonds and the P-H bond lengths are also obtained using the experimentally determined rotational constants. With the increasing of the inversion vibrational excitations (nu2+), the bond lengths (P-H) increase a little and the bond angles (H-P-H) decrease a lot. The inversion vibrational energy levels have also been calculated by using one dimensional potential model and the results are in good agreement with the experimental data for the first several vibrational levels. In addition to inversion vibration, we also observed firstly the other two vibrational modes: the symmetric P-H stretching vibration (nu1+) and the degenerate bending vibration (nu4+). The fundamental frequencies for nu1+ and nu4+ are 2461.6 (+/-2) and 1043.9 (+/-2) cm(-1), respectively. The first IE for PH3 was determined as 79670.9 (+/-1) cm(-1).
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Affiliation(s)
- Jie Yang
- Department of Physics, Tsinghua University, Beijing 100084, China
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41
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Halonen M, Halonen L. Abnormal inversion splitting in NH2D: rotational analysis of the nu5 bending vibrational band system. J Phys Chem A 2006; 110:7554-9. [PMID: 16774196 DOI: 10.1021/jp061287a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A high-resolution Fourier transform infrared spectrum of the nu(5) bending vibrational band system region of the partially deuterated ammonia molecule NH(2)D has been measured and rotationally analyzed. The spectrum consists of strong a-type transitions between the states of same vibrational symmetry and weaker c-type transitions between the states of different vibrational symmetry. The Hamiltonian model used includes interaction terms between the rotational states of both upper and lower inversion doublets. The vibrational term values for the symmetric and the antisymmetric component of the upper-inversion doublet are 1,605.637 965(620) cm(-1) and 1,590.993 82(100) cm(-1), respectively, where the numbers in parentheses are one-standard deviations in the least significant digit. These figures are close to the corresponding values 1,605.62 cm(-1) and 1,590.72 cm(-1) obtained recently from results based on high-level ab initio calculations. The order of the vibrational term values is abnormal in the ammonia family, as typically the symmetric state is lower in wavenumber than the antisymmetric one.
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Affiliation(s)
- Marjo Halonen
- Laboratory of Physical Chemistry, P.O. Box 55, A.I. Virtasen aukio 1, FIN-00014 University of Helsinki, Finland
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42
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Nangia S, Truhlar DG. Direct calculation of coupled diabatic potential-energy surfaces for ammonia and mapping of a four-dimensional conical intersection seam. J Chem Phys 2006; 124:124309. [PMID: 16599676 DOI: 10.1063/1.2168447] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We used multiconfiguration quasidegenerate perturbation theory and the fourfold-way direct diabatization scheme to calculate ab initio potential-energy surfaces at 3600 nuclear geometries of NH3. The calculations yield the adiabatic and diabatic potential-energy surfaces for the ground and first electronically excited singlet states and also the diabatic coupling surfaces. The diabatic surfaces and coupling were fitted analytically to functional forms to obtain a permutationally invariant 2 x 2 diabatic potential-energy matrix. An analytic representation of the adiabatic potential-energy surfaces is then obtained by diagonalizing the diabatic potential-energy matrix. The analytic representation of the surfaces gives an analytic representation of the four-dimensional conical intersection seam which is discussed in detail.
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Affiliation(s)
- Shikha Nangia
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, USA.
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43
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Yurchenko SN, Zheng J, Lin H, Jensen P, Thiel W. Potential-energy surface for the electronic ground state of NH3 up to 20000cm−1 above equilibrium. J Chem Phys 2005; 123:134308. [PMID: 16223289 DOI: 10.1063/1.2047572] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Ab initio coupled cluster calculations with single and double substitutions and a perturbative treatment of connected triple excitations [CCSD(T)] with the augmented correlation-consistent polarized valence triple-zeta aug-cc-pVTZ basis at 51 816 geometries provide a six-dimensional potential-energy surface for the electronic ground state of NH3. At 3814 selected geometries, CBS+ energies are obtained by extrapolating the CCSD(T) results for the aug-cc-pVXZ(X=T,Q,5) basis sets to the complete basis set (CBS) limit and adding corrections for core-valence correlation and relativistic effects. CBS** ab initio energies are generated at 51,816 geometries by an empirical extrapolation of the CCSD(T)/aug-cc-pVTZ results to the CBS+ limit. They cover the energy region up to 20,000 cm-1 above equilibrium. Parametrized analytical functions are fitted through the ab initio points. For these analytical surfaces, vibrational term values and transition moments are calculated by means of a variational program employing a kinetic-energy operator expressed in the Eckart-Sayvetz frame. Comparisons against experiment are used to assess the quality of the generated potential-energy surfaces. A "spectroscopic" potential-energy surface of NH3 is determined by a slight empirical adjustment of the ab initio potential to the experimental vibrational term values. Variational calculations on this refined surface yield rms deviations from experiment of 0.8 cm-1 for 24 inversion splittings and 0.4 (3.0) cm-1 for 34 (51) vibrational term values up to 6100 (10,300) cm-1.
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Affiliation(s)
- Sergei N Yurchenko
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany
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44
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Deskevich MP, Nesbitt DJ. Large amplitude quantum mechanics in polyatomic hydrides. I. A particles-on-a-sphere model for XHn. J Chem Phys 2005; 123:084304. [PMID: 16164288 DOI: 10.1063/1.1940613] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
A framework is presented for converged quantum mechanical calculations on large amplitude dynamics in polyatomic hydrides (XH(n)) based on a relatively simple, but computationally tractable, "particles-on-a-sphere" (POS) model for the intramolecular motion of the light atoms. The model assumes independent two-dimensional (2D) angular motion of H atoms imbedded on the surface of a sphere with an arbitrary interatomic angular potential. This assumption permits systematic evolution from "free rotor" to "tunneling" to "quasi-rigid" polyatomic molecule behavior for small, but finite, values of total angular momentum J. This work focuses on simple triatom (n=2) and tetratom (n=3) systems as a function of interatomic potential stiffness, with explicit consideration of H2O, NH3, and H3O+ as limiting test cases. The POS model also establishes the necessary mathematical groundwork for calculations on dynamically much more challenging XH(n) species with n>3 (e.g., models of CH5+) where such a reduced dimensionality approach offers prospects for being quantum mechanically tractable at low J values (i.e., J=0, 1, 2) characteristic of supersonic jet expansion conditions.
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Affiliation(s)
- Michael P Deskevich
- JILA, National Institute of Standards and Technology and University of Colorado, Department of Chemistry and Biochemistry, Boulder, Colorado 80309-0440, USA
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Dong F, Uy D, Davis S, Child M, Nesbitt DJ. Supersonically cooled hydronium ions in a slit-jet discharge: High-resolution infrared spectroscopy and tunneling dynamics of HD2O+. J Chem Phys 2005; 122:224301. [PMID: 15974662 DOI: 10.1063/1.1924699] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Jet-cooled high-resolution infrared spectra of partially deuterated hydronium ion (HD2O+) in the O-H stretch region (nu3 band) are obtained for the first time, exploiting the high ion densities, long absorption path lengths, and concentration modulation capabilities of the slit-jet discharge spectrometer. Least-squares analysis with a Watson asymmetric top Hamiltonian yields rovibrational constants and provides high level tests of ab initio molecular structure predictions. Transitions out of both the lower (nu3(+)<--0(+)) and the upper (nu3(-)<--0(-)) tunneling levels, as well as transitions across the tunneling gap (nu3(-)<--0(+)) are observed. The nu3(-)<--0(+) transitions in HD2O+ acquire oscillator strength by loss of D(3h) symmetry, and permit both ground-state-[27.0318(72) cm(-1)] and excited-state-[17.7612(54) cm(-1)]-tunneling splittings to be determined to spectroscopic precision from a single rovibrational band. The splittings and band origins calculated with recent high level ab initio six-dimensional potential surface predictions for H3O+ and isotopomers [X. C. Huang, S. Carter, and J. M. Bowman, J. Chem. Phys. 118, 5431 (2003); T. Rajamaki, A. Miani, and L. Halonen, J. Chem. Phys. 118, 10929 (2003)] are in very good agreement with the current experimental results.
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Affiliation(s)
- Feng Dong
- JILA, National Institute of Standards and Technology, University of Colorado, Boulder, Colorado 80309, USA
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Yurchenko ∥ SN, Carvajal M, Jensen * P, Lin ⊥ H, Zheng J, Thiel * W. Rotation–vibration motion of pyramidal XY3molecules described in the Eckart frame: Theory and application to NH3. Mol Phys 2005. [DOI: 10.1080/002689705412331517255] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Linguerri R, Navizet I, Rosmus P, Carter S, Maier JP. Vibrations in the B4 rhombic structure. J Chem Phys 2005; 122:34301. [PMID: 15740195 DOI: 10.1063/1.1828045] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
A double minimum six-dimensional potential energy surface (PES) is determined in symmetry coordinates for the most stable rhombic (D2h) B4 isomer in its 1Ag electronic ground state by fitting to energies calculated ab initio. The PES exhibits a barrier to the D4h square structure of 255 cm(-1). The vibrational levels (J=0) are calculated variationally using an approach which involves the Watson kinetic energy operator expressed in normal coordinates. The pattern of about 65 vibrational levels up to 1600 cm(-1) for all stable isotopomers is analyzed. Analogous to the inversion in ammonia-like molecules, the rhombus rearrangements lead to splittings of the vibrational levels. In B4 it is the B1g (D4h) mode which distorts the square molecule to its planar rhombic form. The anharmonic fundamental vibrational transitions of 11B4 are calculated to be (splittings in parentheses): G(0)=2352(22) cm(-1), nu1(A1g)=1136(24) cm(-1), nu2(B1g)=209(144) cm(-1), nu3(B2g)=1198(19) cm(-1), nu4(B2u)=271(24) cm(-1), and nu5(Eu)=1030(166) cm(-1) (D4h notation). Their variations in all stable isotopomers were investigated. Due to the presence of strong anharmonic resonances between the B1g in-plane distortion and the B2u out-of-plane bending modes, the higher overtones and combination levels are difficult to assign unequivocally.
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Affiliation(s)
- Roberto Linguerri
- Laboratoire de Chimie Théorique, Université de Marne la Vallée, F-77454 Champs sur Marne, France
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Yurchenko SN, Thiel W, Carvajal M, Lin H, Jensen P. Rotation–Vibration Motion of Pyramidal XY3 Molecules Described in the Eckart Frame: The Calculation of Intensities with Application to NH3. ADVANCES IN QUANTUM CHEMISTRY 2005. [DOI: 10.1016/s0065-3276(05)48014-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Rajamäki † T, Kállay M, Noga J, Valiron P, Halonen * L. High excitations in coupled-cluster series: vibrational energy levels of ammonia. Mol Phys 2004. [DOI: 10.1080/00268970412331292759] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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50
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Rajamäki † T, Noga J, Valiron P, Halonen * L. Inversion levels of H3O+as a probe for the basis set convergence in traditional and explicitly correlated coupled-cluster calculations. Mol Phys 2004. [DOI: 10.1080/00268970412331287197] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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