1
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Zhang Y, Wang Y, Xu X, Chen Z, Yang Y. Vibrational Spectra of Highly Anharmonic Water Clusters: Molecular Dynamics and Harmonic Analysis Revisited with Constrained Nuclear-Electronic Orbital Methods. J Chem Theory Comput 2023; 19:9358-9368. [PMID: 38096546 DOI: 10.1021/acs.jctc.3c01037] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2023]
Abstract
Vibrational spectroscopy is widely used to gain insights into structural and dynamic properties of chemical, biological, and materials systems. Thus, an efficient and accurate method to simulate vibrational spectra is desired. In this paper, we justify and employ a microcanonical molecular simulation scheme to calculate the vibrational spectra of three challenging water clusters: the neutral water dimer (H4O2), the protonated water trimer (H7O3+), and the protonated water tetramer (H9O4+). We find that with the accurate description of quantum nuclear delocalization effects through the constrained nuclear-electronic orbital framework, including vibrational mode coupling effects through molecular dynamics simulations can additionally improve the vibrational spectrum calculations. In contrast, without the quantum nuclear delocalization picture, conventional ab initio molecular dynamics may even lead to less accurate results than harmonic analysis.
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Affiliation(s)
- Yuzhe Zhang
- Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Yiwen Wang
- Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Xi Xu
- Center for Advanced Materials Research, Beijing Normal University, Zhuhai 519087, China
| | - Zehua Chen
- Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Yang Yang
- Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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2
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Khuu T, Schleif T, Mohamed A, Mitra S, Johnson MA, Valdiviezo J, Heindel JP, Head-Gordon T. Intra-cluster Charge Migration upon Hydration of Protonated Formic Acid Revealed by Anharmonic Analysis of Cold Ion Vibrational Spectra. J Phys Chem A 2023; 127:7501-7509. [PMID: 37669457 DOI: 10.1021/acs.jpca.3c03971] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/07/2023]
Abstract
The rates of many chemical reactions are accelerated when carried out in micron-sized droplets, but the molecular origin of the rate acceleration remains unclear. One example is the condensation reaction of 1,2-diaminobenzene with formic acid to yield benzimidazole. The observed rate enhancements have been rationalized by invoking enhanced acidity at the surface of methanol solvent droplets with low water content to enable protonation of formic acid to generate a cationic species (protonated formic acid or PFA) formed by attachment of a proton to the neutral acid. Because PFA is the key feature in this reaction mechanism, vibrational spectra of cryogenically cooled, microhydrated PFA·(H2O)n=1-6 were acquired to determine how the extent of charge localization depends on the degree of hydration. Analysis of these highly anharmonic spectra with path integral ab initio molecular dynamics simulations reveals the gradual displacement of the excess proton onto the water network in the microhydration regime at low temperatures with n = 3 as the tipping point for intra-cluster proton transfer.
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Affiliation(s)
- Thien Khuu
- Sterling Chemistry Laboratory, Department of Chemistry, Yale University, New Haven, Connecticut 06511, United States
| | - Tim Schleif
- Sterling Chemistry Laboratory, Department of Chemistry, Yale University, New Haven, Connecticut 06511, United States
| | - Ahmed Mohamed
- Sterling Chemistry Laboratory, Department of Chemistry, Yale University, New Haven, Connecticut 06511, United States
| | - Sayoni Mitra
- Sterling Chemistry Laboratory, Department of Chemistry, Yale University, New Haven, Connecticut 06511, United States
| | - Mark A Johnson
- Sterling Chemistry Laboratory, Department of Chemistry, Yale University, New Haven, Connecticut 06511, United States
| | - Jesús Valdiviezo
- Pitzer Theory Center, Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Joseph P Heindel
- Pitzer Theory Center, Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Teresa Head-Gordon
- Pitzer Theory Center, Department of Chemistry, University of California, Berkeley, California 94720, United States
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3
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Brünig FN, Hillmann P, Kim WK, Daldrop JO, Netz RR. Proton-transfer spectroscopy beyond the normal-mode scenario. J Chem Phys 2022; 157:174116. [DOI: 10.1063/5.0116686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
A stochastic theory is developed to predict the spectral signature of proton-transfer processes and is applied to infrared spectra computed from ab initio molecular-dynamics simulations of a single [Formula: see text] cation. By constraining the oxygen atoms to a fixed distance, this system serves as a tunable model for general proton-transfer processes with variable barrier height. Three spectral contributions at distinct frequencies are identified and analytically predicted: the quasi-harmonic motion around the most probable configuration, amenable to normal-mode analysis, the contribution due to transfer paths when the proton moves over the barrier, and a shoulder for low frequencies stemming from the stochastic transfer-waiting-time distribution; the latter two contributions are not captured by normal-mode analysis but exclusively reported on the proton-transfer kinetics. In accordance with reaction rate theory, the transfer-waiting-contribution frequency depends inversely exponentially on the barrier height, whereas the transfer-path-contribution frequency is rather insensitive to the barrier height.
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Affiliation(s)
- Florian N. Brünig
- Department of Physics, Freie Universität Berlin, 14195 Berlin, Germany
| | - Paul Hillmann
- Department of Physics, Freie Universität Berlin, 14195 Berlin, Germany
| | - Won Kyu Kim
- School of Computational Sciences, Korea Institute for Advanced Study, Seoul 02455, Republic of Korea
| | - Jan O. Daldrop
- Department of Physics, Freie Universität Berlin, 14195 Berlin, Germany
| | - Roland R. Netz
- Department of Physics, Freie Universität Berlin, 14195 Berlin, Germany
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4
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Brünig FN, Rammler M, Adams EM, Havenith M, Netz RR. Spectral signatures of excess-proton waiting and transfer-path dynamics in aqueous hydrochloric acid solutions. Nat Commun 2022; 13:4210. [PMID: 35864099 PMCID: PMC9304333 DOI: 10.1038/s41467-022-31700-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 06/22/2022] [Indexed: 11/23/2022] Open
Abstract
The theoretical basis for linking spectral signatures of hydrated excess protons with microscopic proton-transfer mechanisms has so far relied on normal-mode analysis. We introduce trajectory-decomposition techniques to analyze the excess-proton dynamics in ab initio molecular-dynamics simulations of aqueous hydrochloric-acid solutions beyond the normal-mode scenario. We show that the actual proton transfer between two water molecules involves for relatively large water-water separations crossing of a free-energy barrier and thus is not a normal mode, rather it is characterized by two non-vibrational time scales: Firstly, the broadly distributed waiting time for transfer to occur with a mean value of 200-300 fs, which leads to a broad and weak shoulder in the absorption spectrum around 100 cm-1, consistent with our experimental THz spectra. Secondly, the mean duration of a transfer event of about 14 fs, which produces a rather well-defined spectral contribution around 1200 cm-1 and agrees in location and width with previous experimental mid-infrared spectra.
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Affiliation(s)
- Florian N Brünig
- Freie Universität Berlin, Department of Physics, 14195, Berlin, Germany
| | - Manuel Rammler
- Freie Universität Berlin, Department of Physics, 14195, Berlin, Germany
| | - Ellen M Adams
- Ruhr-Universität Bochum, Department of Physical Chemistry II, 44780, Bochum, Germany
| | - Martina Havenith
- Ruhr-Universität Bochum, Department of Physical Chemistry II, 44780, Bochum, Germany
| | - Roland R Netz
- Freie Universität Berlin, Department of Physics, 14195, Berlin, Germany.
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5
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Towards complete assignment of the infrared spectrum of the protonated water cluster H +(H 2O) 21. Nat Commun 2021; 12:6141. [PMID: 34686665 PMCID: PMC8536673 DOI: 10.1038/s41467-021-26284-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 09/22/2021] [Indexed: 11/08/2022] Open
Abstract
The spectroscopic features of protonated water species in dilute acid solutions have been long sought after for understanding the microscopic behavior of the proton in water with gas-phase water clusters H+(H2O)n extensively studied as bottom-up model systems. We present a new protocol for the calculation of the infrared (IR) spectra of complex systems, which combines the fragment-based Coupled Cluster method and anharmonic vibrational quasi-degenerate perturbation theory, and demonstrate its accuracy towards the complete and accurate assignment of the IR spectrum of the H+(H2O)21 cluster. The site-specific IR spectral signatures reveal two distinct structures for the internal and surface four-coordinated water molecules, which are ice-like and liquid-like, respectively. The effect of inter-molecular interaction between water molecules is addressed, and the vibrational resonance is found between the O-H stretching fundamental and the bending overtone of the nearest neighboring water molecule. The revelation of the spectral signature of the excess proton offers deeper insight into the nature of charge accommodation in the extended hydrogen-bonding network underpinning this aqueous cluster. Protonated water species have been the subject of numerous experimental and computational studies. Here the authors provide a nearly complete assignment of the experimental IR spectrum of the H+(H2O)21 water cluster based on high-level wavefunction theory and anharmonic vibrational quasi-degenerate perturbation theory.
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6
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Inakollu VSS, Yu H. Comparative studies of IR spectra of deprotonated serine with classical and thermostated ring polymer molecular dynamics simulations. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2021; 8:054101. [PMID: 34549074 PMCID: PMC8443303 DOI: 10.1063/4.0000124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 08/30/2021] [Indexed: 06/13/2023]
Abstract
Here we report the vibrational spectra of deprotonated serine calculated from the classical molecular dynamics (MD) simulations and thermostated ring-polymer molecular dynamics (TRPMD) simulation with third-order density-functional tight-binding. In our earlier study [Inakollu and Yu, "A systematic benchmarking of computational vibrational spectroscopy with DFTB3: Normal mode analysis and fast Fourier transform dipole autocorrelation function," J. Comput. Chem. 39, 2067 (2018)] of deprotonated serine, we observed a significant difference in the vibrational spectra with the classical MD simulations compared to the infrared multiple photon dissociation spectra. It was postulated that this is due to neglecting the nuclear quantum effects (NQEs). In this work, NQEs are considered in spectral calculation using the TRPMD simulations. With the help of potential of mean force calculations, the conformational space of deprotonated serine is analyzed and used to understand the difference in the spectra of classical MD and TRPMD simulations at 298.15 and 100 K. The high-frequency vibrational bands in the spectra are characterized using Fourier transform localized vibrational mode (FT-νN AC) and interatomic distance histograms. At room temperature, the quantum effects are less significant, and the free energy profiles in the classical MD and the TRPMD simulations are very similar. However, the hydrogen bond between the hydroxyl-carboxyl bond is slightly stronger in TRPMD simulations. At 100 K, the quantum effects are more prominent, especially in the 2600-3600 cm-1, and the free energy profile slightly differs between the classical MD and TRPMD simulations. Using the FT-νN AC and the interatomic distance histograms, the high-frequency vibrational bands are discussed in detail.
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Affiliation(s)
| | - Haibo Yu
- Author to whom correspondence should be addressed:
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7
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Kwan V, Consta S. Molecular Characterization of the Surface Excess Charge Layer in Droplets. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:33-45. [PMID: 32597645 DOI: 10.1021/jasms.0c00053] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The surface excess charge layer (SECL) in droplets has often been associated with distinct chemistry. We examine the effect of the nature of ions in the composition and structure of SECL by using molecular dynamics. We find that in the presence of simple ions the thickness of SECL is invariant not only with respect to droplet size but also with respect to the nature of the ions. In the presence of simple ions, this layer has a thickness of ∼1.5-1.7 nm but in the presence of macroions it may extend to ∼2.0 nm. The proportion of ions contained in SECL depends on the nature of the ions and the droplet size. For the same droplet size, I- and model H3O+ ions show considerably higher concentration than Na+ and Cl- ions. We identify the maximum ion concentration region, which, in nanodrops, may partially overlap with SECL. As the relative shape fluctuations decrease when microdrop size is approached, the overlap between SECL and maximum ion concentration region increases. We suggest the extension of the bilayer droplet structure assumed in the equilibrium partitioning model of Enke to include the maximum ion concentration region that may not coincide with SECL in nanodrops. We compute the ion concentrations in SECL, which are those that should enter the kinetic equation in the ion-evaporation mechanism, instead of the overall drop ion concentration that has been used.
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Affiliation(s)
- Victor Kwan
- Department of Chemistry, The University of Western Ontario, London, Ontario, Canada N6A 5B7
| | - Styliani Consta
- Department of Chemistry, The University of Western Ontario, London, Ontario, Canada N6A 5B7
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8
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Direct Synthesis of Dimethyl Ether from Syngas on Bifunctional Hybrid Catalysts Based on Supported H3PW12O40 and Cu-ZnO(Al): Effect of Heteropolyacid Loading on Hybrid Structure and Catalytic Activity. Catalysts 2020. [DOI: 10.3390/catal10091071] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The performance of bifunctional hybrid catalysts based on phosphotungstic acid (H3PW12O40, HPW) supported on TiO2 combined with Cu-ZnO(Al) catalyst in the direct synthesis of dimethyl ether (DME) from syngas has been investigated. We studied the effect of the HPW loading on TiO2 (from 1.4 to 2.7 monolayers) on the dispersion and acid characteristics of the HPW clusters. When the concentration of the heteropoliacid is slightly higher than the monolayer (1.4 monolayers) the acidity of the clusters is perturbed by the surface of titania, while for concentration higher than 1.7 monolayers results in the formation of three-dimensional HPW nanocrystals with acidity similar to the bulk heteropolyacid. Physical hybridization of supported heteropolyacids with the Cu-ZnO(Al) catalyst modifies both the acid characteristics of the supported heteropolyacids and the copper surface area of the Cu-ZnO(Al) catalyst. Hybridization gives rise to a decrease in the copper surface area and the disappearance of the strong acidic sites typical of HPW nanocrystals, showing all hybrids similar acid sites of weak or medium strength. The activity of the hybrids was tested for direct DME synthesis from syngas at 30 bar and 250 °C; only the hybrids with HPW loading higher than 1.4 monolayers showed activity for the direct synthesis of DME, showing that the sample loaded with 2.7 monolayers of heteropolyacid had higher activity than the reference hybrid representative of the most widely applied catalysts based on the combination of Cu-ZnO(Al) with HZSM-5. In spite of the high activity of the hybrids, they show a moderate loss in the DME production with TOS that denotes some kind of deactivation of the acidity function under reaction conditions.
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9
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Lebedev AV. The H3O+(H2O)n Reagent Ion: Calculations of the Structure, Thermodynamic Parameters of Hydration, Equilibrium Composition, and Mobility. JOURNAL OF ANALYTICAL CHEMISTRY 2019. [DOI: 10.1134/s1061934819130082] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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10
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Samala NR, Agmon N. Temperature Dependence of Intramolecular Vibrational Bands in Small Water Clusters. J Phys Chem B 2019; 123:9428-9442. [PMID: 31553613 DOI: 10.1021/acs.jpcb.9b07777] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Cyclic water clusters are pivotal for understanding atmospheric reactions as well as liquid water, yet the temperature (T) dependence of their dynamics and spectroscopy is poorly studied. The development of highly accurate water potentials, such as MB-pol, partly rectifies this. It remains to account for the quantum nuclear effects (NQE), because quantum nuclear dynamics become increasingly inaccurate at low temperatures. From a practical point of view, we find that NQE can be accounted for simply by subtracting a constant from the frequencies obtained from the velocity autocorrelation functions (VACF) of classical nuclear dynamics, resulting in unprecedented agreement with experiment, mostly within 5 cm-1. We have performed classical simulations of (H2O)n clusters (n = 2-5) from 20 K and up to their melting temperature, calculating both all-atom and partial VACF, thus generating the temperature dependence of the vibrational frequencies (IR and Raman bands). Focusing on the hydrogen-bonded (HBed) OH stretch and HOH bend, we find opposing T dependencies. The HBed OH modes blue shift linearly with T, attributed to ring expansion rather than any specific conformational change. The lowest-frequency Raman concerted mode is predicted to show the largest such shift. In contrast, the HOH bend undergoes a red-shift, with the highest frequency concerted band undergoing the largest red-shift. These results can be explained by a coupled-oscillator model for n hydrogen atoms on a ring, constrained to move either tangentially (stretch) or perpendicularly (bend) to the ring. With increasing temperature and weakening of HBs, the intrinsic force constant increases (stretch) or remains constant (bend), while the nearest-neighbor coupling constant decreases, and this results in the interesting behavior revealed herein. T-dependent Raman studies are required for testing some of these predictions.
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Affiliation(s)
- Nagaprasad Reddy Samala
- The Fritz Haber Research Center, Institute of Chemistry , The Hebrew University of Jerusalem , Jerusalem 91904 , Israel
| | - Noam Agmon
- The Fritz Haber Research Center, Institute of Chemistry , The Hebrew University of Jerusalem , Jerusalem 91904 , Israel
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11
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Quantum structural fluctuations of protonated water clusters (H2O) H+ (n = 1 − 4) studied by variational molecular dynamics method. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.03.170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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12
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Yu Q, Bowman JM. Classical, Thermostated Ring Polymer, and Quantum VSCF/VCI Calculations of IR Spectra of H7O3+ and H9O4+ (Eigen) and Comparison with Experiment. J Phys Chem A 2019; 123:1399-1409. [DOI: 10.1021/acs.jpca.8b11603] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Qi Yu
- Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Joel M. Bowman
- Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
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13
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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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15
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Heindel JP, Yu Q, Bowman JM, Xantheas SS. Benchmark Electronic Structure Calculations for H3O+(H2O)n, n = 0–5, Clusters and Tests of an Existing 1,2,3-Body Potential Energy Surface with a New 4-Body Correction. J Chem Theory Comput 2018; 14:4553-4566. [DOI: 10.1021/acs.jctc.8b00598] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Joseph P. Heindel
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - 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
| | - Sotiris S. Xantheas
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
- Advanced Computing, Mathematics and Data Division, Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box
999, MS K1-83, Richland, Washington 99352, United States
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16
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Shi R, Li K, Su Y, Tang L, Huang X, Sai L, Zhao J. Revisit the landscape of protonated water clusters H +(H 2O) n with n = 10-17: An ab initio global search. J Chem Phys 2018; 148:174305. [PMID: 29739201 DOI: 10.1063/1.5026383] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Using a genetic algorithm incorporated with density functional theory, we explore the ground state structures of protonated water clusters H+(H2O)n with n = 10-17. Then we re-optimize the isomers at B97-D/aug-cc-pVDZ level of theory. The extra proton connects with a H2O molecule to form a H3O+ ion in all H+(H2O)10-17 clusters. The lowest-energy structures adopt a monocage form at n = 10-16 and core-shell structure at n = 17 based on the MP2/aug-cc-pVTZ//B97-D/aug-cc-pVDZ+ZPE single-point-energy calculation. Using second-order vibrational perturbation theory, we further calculate the infrared spectra with anharmonic correction for the ground state structures of H+(H2O)10-17 clusters at the PBE0/aug-cc-pVDZ level. The anharmonic correction to the spectra is crucial since it reproduces the experimental results quite well. The extra proton weakens the O-H bond strength in the H3O+ ion since the Wiberg bond order of the O-H bond in the H3O+ ion is smaller than that in H2O molecules, which causes a red shift of the O-H stretching mode in the H3O+ ion.
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Affiliation(s)
- Ruili Shi
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024, China
| | - Keyao Li
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024, China
| | - Yan Su
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024, China
| | - Lingli Tang
- College of Science, Dalian Minzu University, Dalian 116600, China
| | - Xiaoming Huang
- School of Ocean Science and Technology, Dalian University of Technology, Panjin Campus, Panjin 124221, China
| | - Linwei Sai
- Department of Mathematics and Physics, Hohai University, Changzhou 213022, China
| | - Jijun Zhao
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024, China
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17
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Affiliation(s)
- Chen Qu
- Department of Chemistry, Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Qi Yu
- Department of Chemistry, Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Joel M. Bowman
- Department of Chemistry, Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
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18
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Esser TK, Knorke H, Asmis KR, Schöllkopf W, Yu Q, Qu C, Bowman JM, Kaledin M. Deconstructing Prominent Bands in the Terahertz Spectra of H 7O 3+ and H 9O 4+: Intermolecular Modes in Eigen Clusters. J Phys Chem Lett 2018; 9:798-803. [PMID: 29360366 DOI: 10.1021/acs.jpclett.7b03395] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report experimental vibrational action spectra (210-2200 cm-1) and calculated IR spectra, using recent ab initio potential energy and dipole moment surfaces, of H7O3+ and H9O4+. We focus on prominent far-IR bands, which postharmonic analyses show, arise from two types of intermolecular motions, i.e., hydrogen bond stretching and terminal water wagging modes, that are similar in both clusters. The good agreement between experiment and theory further validates the accuracy of the potential and dipole moment surfaces, which was used in a recent theoretical study that concluded that infrared photodissociation spectra of the cold clusters correspond to the Eigen isomer. The comparison between theory and experiment adds further confirmation of the need of postharmonic analysis for these clusters.
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Affiliation(s)
- Tim K Esser
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig , Linnéstraße 2, 04103 Leipzig, Germany
| | - Harald Knorke
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig , Linnéstraße 2, 04103 Leipzig, Germany
| | - Knut R Asmis
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig , Linnéstraße 2, 04103 Leipzig, Germany
| | - Wieland Schöllkopf
- Fritz-Haber-Institut der Max-Planck-Gesellschaft , Faradayweg 4-6, D-14195 Berlin, Germany
| | - Qi Yu
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University , Atlanta, Georgia 30322, United States
| | - Chen Qu
- 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
| | - Martina Kaledin
- Department of Chemistry and Biochemistry, Kennesaw State University , Kennesaw, Georgia 30144, United States
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19
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Samala NR, Agmon N. Structure, spectroscopy, and dynamics of the phenol-(water)2 cluster at low and high temperatures. J Chem Phys 2017; 147:234307. [DOI: 10.1063/1.5006055] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Nagaprasad Reddy Samala
- The Fritz Haber Research Center, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Noam Agmon
- The Fritz Haber Research Center, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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Duong CH, Gorlova O, Yang N, Kelleher PJ, Johnson MA, McCoy AB, Yu Q, Bowman JM. Disentangling the Complex Vibrational Spectrum of the Protonated Water Trimer, H +(H 2O) 3, with Two-Color IR-IR Photodissociation of the Bare Ion and Anharmonic VSCF/VCI Theory. J Phys Chem Lett 2017; 8:3782-3789. [PMID: 28737922 DOI: 10.1021/acs.jpclett.7b01599] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Vibrational spectroscopy of the protonated water trimer provides a stringent constraint on the details of the potential energy surface (PES) and vibrational dynamics governing excess proton motion far from equilibrium. Here we report the linear spectrum of the cold, bare H+(H2O)3 ion using a two-color, IR-IR photofragmentation technique and follow the evolution of the bands with increasing ion trap temperature. The key low-energy features are insensitive to both D2 tagging and internal energy. The D2-tagged D+(D2O)3 spectrum is reported for the first time, and the isotope dependence of the band pattern is surprisingly complex. These spectra are reproduced by large-scale vibrational configuration interaction calculations based on a new full-dimensional PES, which treat the anharmonic effects arising from large amplitude motion. The results indicate such extensive mode mixing in both isotopologues that one should be cautious about assigning even the strongest features to particular motions, especially for the absorptions that occur close to the intramolecular bending mode of the water molecule.
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Affiliation(s)
- Chinh H Duong
- Sterling Chemistry Laboratory, Yale University , New Haven, Connecticut 06520, United States
| | - Olga Gorlova
- 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
| | - 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
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Yu Q, Bowman JM. High-Level Quantum Calculations of the IR Spectra of the Eigen, Zundel, and Ring Isomers of H +(H 2O) 4 Find a Single Match to Experiment. J Am Chem Soc 2017; 139:10984-10987. [PMID: 28756669 DOI: 10.1021/jacs.7b05459] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The protonated water tetramer H+(H2O)4, often written as the Eigen cluster, H3O+(H2O)3, plays a central role in studies of the hydrated proton. The cluster has been investigated spectroscopically both experimentally and theoretically with some differences and controversies. The major issue stems from the existence of higher-energy Zundel isomers of this cluster and the role these isomers might play in the IR spectra. Settling this fundamental issue is one goal of this Communication, where high-level quantum calculations of the IR spectra of the Eigen and three isomeric forms of this cluster are presented. These calculations make use of a many-body representation of the potential and dipole moment surfaces and VSCF/VCI calculations of vibrational eigenstates and the IR spectrum. The calculated spectra for the Eigen H3O+(H2O)3 and D3O+(D2O)3 isomers compare very well with experiment. The calculated spectra for the cis and trans-Zundel and ring isomers show prominent features that do not match with experiment but which can guide future experiments to search for these interesting and important isomers.
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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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Brehm M, Thomas M. Computing Bulk Phase Raman Optical Activity Spectra from ab initio Molecular Dynamics Simulations. J Phys Chem Lett 2017; 8:3409-3414. [PMID: 28685571 DOI: 10.1021/acs.jpclett.7b01616] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We present our novel methodology for computing Raman optical activity (ROA) spectra of liquid systems from ab initio molecular dynamics (AIMD) simulations. The method is built upon the recent developments to obtain magnetic dipole moments from AIMD and to integrate molecular properties by using radical Voronoi tessellation. These techniques are used to calculate optical activity tensors for large and complex periodic bulk phase systems. Only AIMD simulations are required as input, and no time-consuming perturbation theory is involved. The approach relies only on the total electron density in each time step and can readily be combined with a wide range of electronic structure methods. To the best of our knowledge, these are the first computed ROA spectra for a periodic bulk phase system. As an example, the experimental ROA spectrum of liquid (R)-propylene oxide is reproduced very well.
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Affiliation(s)
- Martin Brehm
- Institut für Chemie - Theoretische Chemie, Martin-Luther-Universität Halle-Wittenberg , Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany
| | - Martin Thomas
- Institut für Chemie - Theoretische Chemie, Martin-Luther-Universität Halle-Wittenberg , Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany
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