1
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Zhang S, Zheng Z, Zhang M, Zhang T, Zhang Z, Huang H. The application of THz-TDS in the characterization of Bayan Obo magnetite ore composition. Sci Rep 2024; 14:15033. [PMID: 38951568 PMCID: PMC11217283 DOI: 10.1038/s41598-024-65772-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Accepted: 06/24/2024] [Indexed: 07/03/2024] Open
Abstract
The application of terahertz time-domain spectroscopy (THz-TDS) in the quantitative analysis of major minerals in Bayan Obo magnetite ore was explored. The positive correlation between the optical parameters of the original ore and its iron content is confirmed. The detections of three main iron containing minerals, including magnetite, pyrite, and hematite, were simulated using corresponding reagents. The random forest algorithm is used for quantitative analysis, and FeS2 is detected with precision of R2 = 0.7686 and MAE = 0.6307% in ternary mixtures. The experimental results demonstrate that THz-TDS can distinguish specific iron containing minerals and reveal the potential application value of this testing method in exploration and mineral processing fields.
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Affiliation(s)
- Siqi Zhang
- School of Science, China University of Geosciences (Beijing), Beijing, 100083, China
| | - Zhiyuan Zheng
- School of Science, China University of Geosciences (Beijing), Beijing, 100083, China.
| | - Mingrui Zhang
- School of Science, China University of Geosciences (Beijing), Beijing, 100083, China
| | - Tong Zhang
- School of Science, China University of Geosciences (Beijing), Beijing, 100083, China
| | - Zili Zhang
- School of Science, China University of Geosciences (Beijing), Beijing, 100083, China
| | - Haochong Huang
- School of Science, China University of Geosciences (Beijing), Beijing, 100083, China.
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2
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Foroutan M, Boudaghi A, Alibalazadeh M. Fullerenes containing water molecules: a study of reactive molecular dynamics simulations. Phys Chem Chem Phys 2023; 25:32493-32502. [PMID: 37997178 DOI: 10.1039/d3cp04420c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2023]
Abstract
A different technique was used to investigate fullerenes encapsulating a polar guest species. By reactive molecular dynamics simulations, three types of fullerenes were investigated on a gold surface: an empty C60, a single H2O molecule inside C60 (H2O@C60), and two water molecules inside C60 ((H2O)2@C60). Our findings revealed that despite the free movement of all fullerenes on gold surfaces, confined H2O molecules within the fullerenes result in a distinct pattern of motion in these systems. The (H2O)2@C60 complex had the highest displacement and average velocity, while C60 had the lowest displacement and average velocity. The symmetry of molecules and the polarity of water seem to be crucial in these cases. ReaxFF simulations showed that water molecules in an H2O molecule, H2O@C60, and (H2O)2@C60 have dipole moments of 1.76, 0.42, and 0.47 D, respectively. A combination of the non-polar C60 and polar water demonstrated a significant reduction in the dipole moment of H2O molecules due to encapsulation. The dipole moments of water molecules agreed with those in other studies, which can be useful in the development of biocompatible and high-efficiency nanocars.
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Affiliation(s)
- Masumeh Foroutan
- Department of Physical Chemistry, School of Chemistry, College of Science, University of Tehran, Tehran, Iran.
| | - Ahmad Boudaghi
- Department of Physical Chemistry, School of Chemistry, College of Science, University of Tehran, Tehran, Iran.
| | - Mahtab Alibalazadeh
- Department of Physical Chemistry, School of Chemistry, College of Science, University of Tehran, Tehran, Iran.
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3
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Balos V, Wolf M, Kovalev S, Sajadi M. Optical rectification and electro-optic sampling in quartz. OPTICS EXPRESS 2023; 31:13317-13327. [PMID: 37157471 DOI: 10.1364/oe.480339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
We report the electro-optic sampling (EOS) response and the terahertz (THz) optical rectification (OR) of the z-cut α-quartz. Due to its small effective second-order nonlinearity, large transparency window and hardness, freestanding thin quartz plates can faithfully measure the waveform of intense THz pulses with MV/cm electric-field strength. We show that both its OR and EOS responses are broad with extension up to ∼8 THz. Strikingly, the latter responses are independent of the crystal thickness, a plausible indication of dominant surface contribution to the total second-order nonlinear susceptibility of quartz at THz frequencies. Our study introduces the crystalline quartz as a reliable THz electro-optic medium for high field THz detection, and characterize its emission as a common substrate.
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4
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Rademacher J, Reedy ES, Negri F, Alom S, Whitby RJ, Levitt MH, Campbell EK. Gas-phase electronic spectroscopy of nuclear spin isomer separated H 2O@C and D 2O@C. Mol Phys 2023. [DOI: 10.1080/00268976.2023.2173507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Affiliation(s)
| | | | - Fabrizia Negri
- Dipartimento di Chimica ‘Giacomo Ciamician’ and INSTM, Università di Bologna, Bologna, Italy
| | - Shamim Alom
- Chemistry, University of Southampton, Southampton, Hants, UK
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5
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Mukherjee K, Palchowdhury S, Maroncelli M. OH Stretching and Libration Bands of Solitary Water in Ionic Liquids and Dipolar Solvents Share a Single Dependence on Solvent Polarity. J Phys Chem B 2022; 126:4584-4598. [PMID: 35687693 DOI: 10.1021/acs.jpcb.2c02445] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Ionic liquids are an emerging class of materials which are finding application in a variety of technologically important areas. Because of their hydrophilic character, at least a small concentration of water is often present when ionic liquids are used in practical applications. This study employs infrared spectroscopy in the OH stretching and libration regions together with DFT calculations to better characterize the state of dilute water in ionic liquids. Water mole fractions (xw ∼ 0.1) are chosen such that nearly all water occurs in monomeric form and spectra probe the solvation structure and dynamics of solitary water molecules. New data are reported for a series of 1-ethyl-3-methylimidazolium liquids [Im21][X] with X- = (C2F5)3F3P-, (CF3SO2)2N-, BF4-, B(CN)4-, CF3SO3-, C2H5SO4-, NO3-, SCN-, and CH3CO2-, as well as for the two 1-hexyl-3-methylimidazolium liquids [Im61][Cl] and [Im61][I]. For comparison, spectra are also recorded in a variety of dipolar solvents, and much of the available literature data are summarized, providing a comprehensive perspective on monomeric water in homogeneous solution. Most prior studies of dilute water in ionic liquids interpreted OH stretching spectra only in terms of water being specifically bonded to two anions in A-···H-O-H···A- type solvates. The more detailed analysis presented here indicates the additional presence of asymmetrically solvated water, which in some cases includes both singly solvated (A-···H-O-H) and more subtle forms of asymmetric solvation. The same pattern of solvation also pertains to dipolar solvents capable of accepting hydrogen bonds from water. No clear distinction is found between OH spectra in high-polarity conventional solvents and ionic liquids. In all solvents, OH frequencies are strongly correlated to measures of solvent basicity or hydrogen bond accepting ability. Far-infrared spectra of the water libration band also show common trends in ionic and dipolar solvents. Despite the different character of the libration and OH modes, the frequencies of these vibrations show virtually the same solvent dependence (apart from sign) except in weakly polar or nonpolar solvents.
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Affiliation(s)
- Kallol Mukherjee
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Sourav Palchowdhury
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Mark Maroncelli
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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6
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Hauser AW, Pototschnig JV. Vibronic Coupling in Spherically Encapsulated, Diatomic Molecules: Prediction of a Renner-Teller-like Effect for Endofullerenes. J Phys Chem A 2022; 126:1674-1680. [PMID: 35258966 PMCID: PMC8935370 DOI: 10.1021/acs.jpca.1c10970] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
In the year 1933,
Herzberg and Teller realized that the potential
energy surface of a triatomic, linear molecule splits into two as
soon as the molecule is bent. The phenomenon, later dubbed the Renner–Teller
effect due to the detailed follow-up work of Renner on the subject,
describes the coupling of a symmetry-reducing molecular vibration
with degenerate electronic states. In this article, we show that a
very similar type of nonadiabatic coupling can occur for certain translational
degrees of freedom of diatomic, electronically degenerate molecules
when trapped in a nearly spherical or cylindrical quantum confinement,
e.g., realized through electromagnetic fields or molecular encapsulation.
We illustrate this on the example of fullerene-encapsulated nitric
oxide, and provide a prediction of its interesting, perturbed vibronic
spectrum.
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Affiliation(s)
- Andreas W Hauser
- Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, 8010 Graz, Austria
| | - Johann V Pototschnig
- Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, 8010 Graz, Austria
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7
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Du S, Hashikawa Y, Ito H, Hashimoto K, Murata Y, Hirayama Y, Hirakawa K. Inelastic Electron Transport and Ortho-Para Fluctuation of Water Molecule in H 2O@C 60 Single Molecule Transistors. NANO LETTERS 2021; 21:10346-10353. [PMID: 34854686 DOI: 10.1021/acs.nanolett.1c03604] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Light molecules such as H2O are the systems in which we can have access to quantum mechanical information on their constituent atoms. Here, we have investigated electron transport through H2O@C60 single molecule transistors (SMTs). The H2O@C60 SMTs exhibit Coulomb stability diagrams that show multiple tunneling-induced excited states below 30 meV. Furthermore, we have performed terahertz (THz) photocurrent spectroscopy on H2O@C60 SMTs and confirmed the same excitations. From comparison between experiment and theory, the excitations observed below 10 meV are identified to be the quantum rotational excitations of the water molecule. Surprisingly, the quantum rotational excitations of both para- and ortho-water molecule are observed simultaneously even for a single water molecule, indicating that the fluctuation between the ortho- and para-water states takes place in a time scale shorter than our measurement time (∼1 min), probably by the interaction between the encapsulated water molecule and conducting electrons.
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Affiliation(s)
- Shaoqing Du
- Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
| | - Yoshifumi Hashikawa
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Haruka Ito
- Graduate School of Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Katsushi Hashimoto
- Graduate School of Sciences, Tohoku University, Sendai 980-8578, Japan
- Centre for Spintronics Research Network, Tohoku University, Sendai 980-8578, Japan
- Center for Science and Innovation in Spintronics (Core Research Cluster), Tohoku University, Sendai 980-8577, Japan
| | - Yasujiro Murata
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Yoshiro Hirayama
- Graduate School of Sciences, Tohoku University, Sendai 980-8578, Japan
- Centre for Spintronics Research Network, Tohoku University, Sendai 980-8578, Japan
- Center for Science and Innovation in Spintronics (Core Research Cluster), Tohoku University, Sendai 980-8577, Japan
| | - Kazuhiko Hirakawa
- Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
- Institute for Nano Quantum Information Electronics, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
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8
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Dolgonos GA. Exploring the Properties of H
2
O@C
60
with the Local Second‐Order Møller‐Plesset Perturbation Theory: Blue or Red Shift in C
60
and H
2
O Fundamentals to Expect? ChemistrySelect 2021. [DOI: 10.1002/slct.202103004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Grygoriy A. Dolgonos
- Institute of Chemistry University of Graz Heinrichstrasse 28/IV A-8010 Graz Austria
- Life Chemicals Inc. Murmanska Str. 5 02660 Kyiv Ukraine
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9
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Bacanu GR, Jafari T, Aouane M, Rantaharju J, Walkey M, Hoffman G, Shugai A, Nagel U, Jiménez-Ruiz M, Horsewill AJ, Rols S, Rõõm T, Whitby RJ, Levitt MH. Experimental determination of the interaction potential between a helium atom and the interior surface of a C 60 fullerene molecule. J Chem Phys 2021; 155:144302. [PMID: 34654304 DOI: 10.1063/5.0066817] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The interactions between atoms and molecules may be described by a potential energy function of the nuclear coordinates. Nonbonded interactions between neutral atoms or molecules are dominated by repulsive forces at a short range and attractive dispersion forces at a medium range. Experimental data on the detailed interaction potentials for nonbonded interatomic and intermolecular forces are scarce. Here, we use terahertz spectroscopy and inelastic neutron scattering to determine the potential energy function for the nonbonded interaction between single He atoms and encapsulating C60 fullerene cages in the helium endofullerenes 3He@C60 and 4He@C60, synthesized by molecular surgery techniques. The experimentally derived potential is compared to estimates from quantum chemistry calculations and from sums of empirical two-body potentials.
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Affiliation(s)
- George Razvan Bacanu
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Tanzeeha Jafari
- National Institute of Chemical Physics and Biophysics, Tallinn 12618, Estonia
| | | | - Jyrki Rantaharju
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Mark Walkey
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Gabriela Hoffman
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Anna Shugai
- National Institute of Chemical Physics and Biophysics, Tallinn 12618, Estonia
| | - Urmas Nagel
- National Institute of Chemical Physics and Biophysics, Tallinn 12618, Estonia
| | | | - Anthony J Horsewill
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Stéphane Rols
- Institut Laue-Langevin, BP 156, 38042 Grenoble, France
| | - Toomas Rõõm
- National Institute of Chemical Physics and Biophysics, Tallinn 12618, Estonia
| | - Richard J Whitby
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Malcolm H Levitt
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
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10
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Chemical shielding of H 2O and HF encapsulated inside a C 60 cage. Commun Chem 2021; 4:135. [PMID: 36697850 PMCID: PMC9814403 DOI: 10.1038/s42004-021-00569-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 08/24/2021] [Indexed: 01/28/2023] Open
Abstract
Molecular surgery provides the opportunity to study relatively large molecules encapsulated within a fullerene cage. Here we determine the location of an H2O molecule isolated within an adsorbed buckminsterfullerene cage, and compare this to the intrafullerene position of HF. Using normal incidence X-ray standing wave (NIXSW) analysis, coupled with density functional theory and molecular dynamics simulations, we show that both H2O and HF are located at an off-centre position within the fullerene cage, caused by substantial intra-cage electrostatic fields generated by surface adsorption of the fullerene. The atomistic and electronic structure simulations also reveal significant internal rotational motion consistent with the NIXSW data. Despite this substantial intra-cage interaction, we find that neither HF or H2O contribute to the endofullerene frontier orbitals, confirming the chemical isolation of the encapsulated molecules. We also show that our experimental NIXSW measurements and theoretical data are best described by a mixed adsorption site model.
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11
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Carrillo-Bohórquez O, Valdés Á, Prosmiti R. Encapsulation of a Water Molecule inside C 60 Fullerene: The Impact of Confinement on Quantum Features. J Chem Theory Comput 2021; 17:5839-5848. [PMID: 34420292 PMCID: PMC8444341 DOI: 10.1021/acs.jctc.1c00662] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Indexed: 11/30/2022]
Abstract
We introduce an efficient quantum fully coupled computational scheme within the multiconfiguration time-dependent Hartree (MCTDH) approach to handle the otherwise extremely costly computations of translational-rotational-vibrational states and energies of light-molecule endofullenes. Quantum calculations on energy levels are reported for a water molecule inside C60 fullerene by means of such a systematic approach that includes all nine degrees of freedom of H2O@C60 and does not consider restrictions above them. The potential energy operator is represented as a sum of natural potentials employing the n-mode expansion, along with the exact kinetic energy operator, by introducing a set of Radau internal coordinates for the H2O molecule. On the basis of the present rigorous computations, various aspects of the quantized intermolecular dynamics upon confinement of H2O@C60 are discussed, such as the rotational energy level splitting and the significant frequency shifts of the encapsulated water molecule vibrations. The impact of water encapsulation on quantum features is explored, and insights into the nature of the underlying forces are provided, highlighting the importance of a reliable first-principles description of the guest-host interactions.
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Affiliation(s)
- Orlando Carrillo-Bohórquez
- Departamento
de Física, Universidad Nacional
de Colombia, Calle 26, Cra 39, 404 Edificio, Bogotá, Colombia
- Institute
of Fundamental Physics (IFF-CSIC), CSIC, Serrano 123, 28006 Madrid, Spain
| | - Álvaro Valdés
- Escuela
de Física, Universidad Nacional
de Colombia, Sede Medellín, A. A 3840 Medellín, Colombia
| | - Rita Prosmiti
- Institute
of Fundamental Physics (IFF-CSIC), CSIC, Serrano 123, 28006 Madrid, Spain
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12
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Shugai A, Nagel U, Murata Y, Li Y, Mamone S, Krachmalnicoff A, Alom S, Whitby RJ, Levitt MH, Rõõm T. Infrared spectroscopy of an endohedral water in fullerene. J Chem Phys 2021; 154:124311. [PMID: 33810704 DOI: 10.1063/5.0047350] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
An infrared absorption spectroscopy study of the endohedral water molecule in a solid mixture of H2O@C60 and C60 was carried out at liquid helium temperature. From the evolution of the spectra during the ortho-para conversion process, the spectral lines were identified as para-H2O and ortho-H2O transitions. Eight vibrational transitions with rotational side peaks were observed in the mid-infrared: ω1, ω2, ω3, 2ω1, 2ω2, ω1 + ω3, ω2 + ω3, and 2ω2 + ω3. The vibrational frequencies ω2 and 2ω2 are lower by 1.6% and the rest by 2.4%, as compared to those of free H2O. A model consisting of a rovibrational Hamiltonian with the dipole and quadrupole moments of H2O interacting with the crystal field was used to fit the infrared absorption spectra. The electric quadrupole interaction with the crystal field lifts the degeneracy of the rotational levels. The finite amplitudes of the pure v1 and v2 vibrational transitions are consistent with the interaction of the water molecule dipole moment with a lattice-induced electric field. The permanent dipole moment of encapsulated H2O is found to be 0.50 ± 0.05 D as determined from the far-infrared rotational line intensities. The translational mode of the quantized center-of-mass motion of H2O in the molecular cage of C60 was observed at 110 cm-1 (13.6 meV).
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Affiliation(s)
- A Shugai
- National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn, Estonia
| | - U Nagel
- National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn, Estonia
| | - Y Murata
- Institute for Chemical Research, Kyoto University, Kyoto 611-0011, Japan
| | - Yongjun Li
- Department of Chemistry, Columbia University, New York, New York 10027, USA
| | - S Mamone
- School of Chemistry, Southampton University, Southampton SO17 1BJ, United Kingdom
| | - A Krachmalnicoff
- School of Chemistry, Southampton University, Southampton SO17 1BJ, United Kingdom
| | - S Alom
- School of Chemistry, Southampton University, Southampton SO17 1BJ, United Kingdom
| | - R J Whitby
- School of Chemistry, Southampton University, Southampton SO17 1BJ, United Kingdom
| | - M H Levitt
- School of Chemistry, Southampton University, Southampton SO17 1BJ, United Kingdom
| | - T Rõõm
- National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn, Estonia
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