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Peng Y, Jiang X, Liu L, Liu G, Zhu H. A new six-dimensional ab initio potential energy surface and rovibrational spectra for the N2-CO2 complex. J Chem Phys 2023; 159:244304. [PMID: 38146833 DOI: 10.1063/5.0182188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 12/04/2023] [Indexed: 12/27/2023] Open
Abstract
New six-dimensional ab initio potential energy surfaces (PESs) for the N2-CO2 complex, which involve the stretching vibration of N2 and the Q3 normal mode for the ν3 asymmetric stretching vibration of CO2, were constructed using the CCSD(T)-F12/AVTZ method with midpoint bond functions. Two vibrational averaged 4D interaction potentials were obtained by integrating over the two intramolecular coordinates. It was found that both PESs possess two equivalent T-shaped global minima as well as two in-plane and one out-of-plane saddle points. Based on these PESs, rovibrational bound states and energy levels were calculated applying the radial discrete variable representation/angular finite basis representation method and the Lanczos algorithm. The splitting of the energy levels between oN2-CO2 and pN2-CO2 for the intermolecular vibrational ground state is determined to be only 0.000 09 cm-1 due to the higher barriers. The obtained band origin shift is about +0.471 74 cm-1 in the N2-CO2 infrared spectra with CO2 at the ν3 zone, which coincides with the experimental data of +0.483 74 cm-1. The frequencies of the in-plane geared-bending for N2-CO2 at the ν3 = 0 and 1 states of CO2 turn out to be 21.6152 and 21.4522 cm-1, the latter reproduces the available experimental 21.3793 cm-1 value with CO2 at the ν3 zone. The spectral parameters fitted from the rovibrational energy levels show that this dimer is a near prolate asymmetric rotor. The computed microwave transitions as well as the infrared fundamental and combination bands for the complex agree well with the observed data.
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Affiliation(s)
- Yang Peng
- School of Chemistry, Sichuan University, Chengdu 610064, China
| | - Xuedan Jiang
- School of Chemistry, Sichuan University, Chengdu 610064, China
| | - Li Liu
- School of Chemistry, Sichuan University, Chengdu 610064, China
| | - Guangliang Liu
- School of Chemistry, Sichuan University, Chengdu 610064, China
| | - Hua Zhu
- School of Chemistry, Sichuan University, Chengdu 610064, China
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Li Y, Zhai Y, Li H. MLRNet: Combining the Physics-Motivated Potential Models with Neural Networks for Intermolecular Potential Energy Surface Construction. J Chem Theory Comput 2023; 19:1421-1431. [PMID: 36826225 DOI: 10.1021/acs.jctc.2c01049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
A physics-based machine learning model called MLRNet has been developed to construct the high-accuracy two-body intermolecular potential energy surface (IPES). The outputs of the neural network are integrated into the physically realistic Morse/long-range (MLR) function, which ensures that the MLRNet has meaningful extrapolation at both short and long ranges and solves the asymptotic problem in common neural network potential (NNP) models. The neural network representation of the MLR parameters is more flexible and more efficient than the polynomial expansion in the conventional mdMLR model, especially for systems containing nonrigid monomer(s). The present work illustrates the basic framework of the current MLRNet model, including (i) how to combine the physically meaningful MLR function with different possible NN structures, (ii) the preservation of permutation symmetry, and (iii) the predetermination of the long-range function uLR. We choose two realistic systems to demonstrate the performance of MLRNet: the three-dimensional IPES of CO2-He including the CO2 antisymmetric vibration Q3 and the six-dimensional IPES of the H2O-Ar system. In both cases, the fitting errors of the MLRNet are several times smaller than those of the conventional mdMLR model. Both short-range and long-range extrapolation tests were performed to illustrate the extrapolation ability of the MLRNet and its damping function version. Moreover, for the 6-D H2O-Ar system, the MLRNet only needs 1596 trainable parameters, which is almost equal to the number needed for the 5-D mdMLR model (1509) and half that needed for the PIP-NN model (3501) within similar accuracy, which illustrates the model efficiency in high-dimensional IPES fitting.
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Affiliation(s)
- You Li
- Institute of Theoretical Chemistry, College of Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130023, P. R. China
| | - Yu Zhai
- Institute of Theoretical Chemistry, College of Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130023, P. R. China
| | - Hui Li
- Institute of Theoretical Chemistry, College of Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130023, P. R. China
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3
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Barclay AJ, McKellar ARW, Moazzen-Ahmadi N. Spectra of CO 2-Rg 2 and CO 2-Rg-He trimers (Rg = Ne, Ar, Kr, and Xe): Intermolecular CO 2 rock, vibrational shifts and three-body effects. J Chem Phys 2022; 157:204303. [DOI: 10.1063/5.0128133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Weakly bound CO2-Rg2 trimers are studied by high-resolution (0.002 cm−1) infrared spectroscopy in the region of the CO2 ν3 fundamental band (≈2350 cm−1), using a tunable optical parametric oscillator to probe a pulsed supersonic slit jet expansion with an effective rotational temperature of about 2 K. CO2–Ar2 spectra have been reported previously, but they are extended here to include Rg = Ne, Kr, and Xe as well as new combination and hot bands. For Kr and Xe, a unified scaled parameter scheme is used to account for the many possible isotopic species. Vibrational shifts of CO2-Rg2 trimers are compared to those of CO2-Rg dimers, and in all cases the trimer shifts are slightly more positive (blue-shifted) than expected on the basis of linear extrapolation from the dimer. Combination bands directly measure an intermolecular vibrational mode (the CO2 rock) and give values of about 32.2, 33.8, and 34.7 cm−1 for CO2–Ar2, –Kr2, and –Xe2. Structural parameters derived for CO2-Rg2 trimers are compared with those of CO2-Rg and Rg2 dimers. Spectra of the mixed trimers CO2-Rg-He are also reported.
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Affiliation(s)
- A. J. Barclay
- Department of Physics and Astronomy, University of Calgary, 2500 University Drive North West, Calgary, Alberta T2N 1N4, Canada
| | - A. R. W. McKellar
- National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada
| | - N. Moazzen-Ahmadi
- Department of Physics and Astronomy, University of Calgary, 2500 University Drive North West, Calgary, Alberta T2N 1N4, Canada
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Peng Y, Zhu F, Zhu H. A new potential energy surface and rovibrational spectra of the CO-CO 2 complex: Dependence on the antisymmetric stretching vibration of CO 2. J Chem Phys 2022; 157:084310. [DOI: 10.1063/5.0100613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a new ab initio five-dimensional potential energy surface for the CO-CO2 complex containing the Q3 normal mode for the ν3 asymmetric stretching vibration of the CO2 unit. The potential was calculated by supermolecular approach at the CCSD(T)-F12 level with aug-cc-pVTZ basis set plus midpoint bond functions. Two vibrationally averaged four-dimensional potentials for CO-CO2 with CO2 in the ground and ν3 excited states were generated by the integration of the five-dimensional potential over the Q3 intramolecular coordinate. Each potential displays a T-shaped global minimum with the C end in the CO unit pointing toward the C atom in the CO2 unit and a T-shaped local minimum but with the CO monomer rotated by 180º. The rovibrational bound states and energy levels for the CO-CO2 dimer were obtained employing the radial discrete variable representation (DVR)/angular finite basis representation (FBR) method in conjunction with the Lanczos algorithm. The vibrational ground and some lower excited states for CO-CO2 are localized around the global minimum because of the higher potential barriers. The band origin is blueshifted by 0.2089 cm-1 for CO-CO2 in the CO2 ν3 range, which is consistent with the experimental result of 0.211 cm-1. The geared bending vibrational frequencies for CO-CO2 are 24.7101 and 24.5549 cm-1 at the ground and ν3 excited states of CO2, respectively. The predicted rovibrational frequencies as well as spectral constants coincide with the available observations, and these parameters show the CO-CO2 complex is a nearly prolate asymmetric rotor.
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Affiliation(s)
- Yang Peng
- Sichuan University College of Chemistry, China
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5
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Schmidt M, Roy PN. On the accuracy and efficiency of different methods to calculate Raman vibrational shifts of parahydrogen clusters. J Chem Phys 2022; 156:084102. [DOI: 10.1063/5.0076403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The Raman vibrational frequency shifts of pure parahydrogen and orthodeuterium clusters of sizes N = 4–9 are calculated using the Langevin equation path integral ground state method. The shifts are calculated using three different methods; the results obtained from each are compared to experiment and variance properties are assessed. The first method requires the direct calculation of energies from two simulations: one when the cluster is in the v = 0 vibrational state and one when the cluster has v = 1 total quantum of vibration. The shift is directly calculated from the difference in those two energies. The second method requires only a v = 0 simulation to be performed. The ground state energy is calculated as usual and the excited state energy is calculated by using the distribution of the v = 0 simulation and the ratio of the density matrices between the v = 1 state and the v = 0 state. The shift is calculated from the difference in those two energies. These first two are both exact methods. The final method is based on perturbation theory where the shift is calculated by averaging the pairwise difference potential over the pair distribution function. However, this is an approximate approach. It is found that for large enough system sizes, despite the approximations, the perturbation theory method has the strongest balance between accuracy and precision when weighing against computational cost.
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Affiliation(s)
- Matthew Schmidt
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Pierre-Nicholas Roy
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
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Ibrahim A, Wang L, Halverson T, Le Roy RJ, Roy PN. Equation of state and first principles prediction of the vibrational matrix shift of solid parahydrogen. J Chem Phys 2019; 151:244501. [PMID: 31893865 DOI: 10.1063/1.5131329] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We generate the equation of state (EOS) of solid parahydrogen (para-H2) using a path-integral Monte Carlo (PIMC) simulation based on a highly accurate first-principles adiabatic hindered rotor potential energy curve for the para-H2 dimer. The EOS curves for the fcc and hcp structures of solid para-H2 near the equilibrium density show that the hcp structure is the more stable of the two, in agreement with experiment. To accurately reproduce the structural and energy properties of solid para-H2, we eliminated by extrapolation the systematic errors associated with the choice of simulation parameters used in the PIMC calculation. We also investigate the temperature dependence of the EOS curves, and the invariance of the equilibrium density with temperature is satisfyingly reproduced. The pressure as a function of density and the compressibility as a function of pressure are both calculated using the obtained EOS and are compared with previous simulation results and experiments. We also report the first ever a priori prediction of a vibrational matrix shift from first-principles two-body potential functions, and its result for the equilibrium state agrees well with experiment.
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Affiliation(s)
- Alexander Ibrahim
- Department of Physics and Astronomy, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - Lecheng Wang
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - Tom Halverson
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - Robert J Le Roy
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - Pierre-Nicholas Roy
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
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7
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Li H, Zhang XL, Zeng T, Le Roy RJ, Roy PN. Suppression of Parahydrogen Superfluidity in a Doped Nanoscale Bose Fluid Mixture. PHYSICAL REVIEW LETTERS 2019; 123:093001. [PMID: 31524438 DOI: 10.1103/physrevlett.123.093001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 06/07/2019] [Indexed: 06/10/2023]
Abstract
Helium (^{4}He) nanodroplets provide a unique environment to observe the microscopic origins of superfluidity. The search for another superfluid substance has been an ongoing quest in the field of quantum fluids. Nearly two decades ago, experiments on doped parahydrogen (p-H_{2}) clusters embedded in ^{4}He droplets displayed anomalous spectroscopic signatures that were interpreted as a sign of the superfluidity of p-H_{2} [S. Grebenev et al., Science 289, 1532 (2000)SCIEAS0036-807510.1126/science.289.5484.1532]. Here, we observe, using first-principles quantum Monte Carlo simulations, a phase separation between a symmetric and localized p-H_{2} core and ^{4}He shells. The p-H_{2} core has minimal superfluid response. These findings are consistent with the recorded spectra but not with their original interpretation, and lead us to conclude that doped p-H_{2} clusters form a nonsuperfluid core in ^{4}He droplets.
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Affiliation(s)
- Hui Li
- Institute of Theoretical Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130023, China
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Xiao-Long Zhang
- Institute of Theoretical Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130023, China
| | - Tao Zeng
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
- Department of Chemistry, Carleton University, Ottawa, Ontario K1S 5B6, Canada
- Department of Chemistry, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada
| | - Robert J Le Roy
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Pierre-Nicholas Roy
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
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8
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Qin M, Xiao X, Zhu H. Theoretical calculation of a full-dimensional ab initio potential energy surface and prediction of infrared spectra for Xe–CS 2. RSC Adv 2019; 9:20925-20930. [PMID: 35515540 PMCID: PMC9066011 DOI: 10.1039/c9ra03782a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 07/22/2019] [Accepted: 06/17/2019] [Indexed: 11/22/2022] Open
Abstract
An effective four-dimensional (4D) ab initio potential energy surface (PES) for Xe–CS2 which explicitly involves the intramolecular Q1 symmetric stretching and Q3 antisymmetric stretching vibrational coordinates of CS2 is constructed. The computations are carried out employing single- and double-excitation coupled-cluster theory with a non-iterative perturbation treatment of triple excitations [CCSD(T)] method with a large basis set. Two vibrationally averaged potentials at the ground and ν1 + ν3 (ν1 = 1, ν3 = 1) excited states are obtained by integrating the 4D potentials over the Q1 and Q3 coordinates. The potentials have a T-shaped global minimum and two equivalent linear local minima. The radial discrete variable representation/angular finite basis representation and the Lanczos algorithm are employed to calculate the rovibrational energy levels for Xe–CS2. The infrared band origin shift associated with the fundamental band of CS2 is predicted, which is red-shifted by −1.996 cm−1 in the ν1 + ν3 region. In addition, we further predict the spectroscopic parameters for the ground and the ν1 + ν3 excited states of Xe–CS2. Compared with the previous Rg–CS2 (Rg = He, Ne, Ar, Kr) complexes, we found that the complexes of the rare gas atoms with CS2 display obvious regularities. Contour plot (in cm−1) of the averaged intermolecular potential energy surface for Xe–CS2 with CS2 at the ν1 + ν3 excited state.![]()
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Affiliation(s)
- Miao Qin
- School of Architectural and Environmental Engineering
- Chengdu Technological University
- Chengdu 611730
- China
- Center of Big Data for Smart Environmental Protection
| | - Xiuchan Xiao
- School of Architectural and Environmental Engineering
- Chengdu Technological University
- Chengdu 611730
- China
- Center of Big Data for Smart Environmental Protection
| | - Hua Zhu
- School of Chemistry
- Sichuan University
- Chengdu 610064
- China
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9
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Zhai Y, Li H, Le Roy RJ. Constructing high-accuracy intermolecular potential energy surface with multi-dimension Morse/Long-Range model. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1429687] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Yu Zhai
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun, China
| | - Hui Li
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun, China
| | - Robert J. Le Roy
- Department of Chemistry, University of Waterloo, Waterloo, Canada
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10
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Faulkner T, Miller I, Raston PL. Quantum cascade laser spectroscopy of OCS isotopologues in 4He nanodroplets: A test of adiabatic following for a heavy rotor. J Chem Phys 2018; 148:044308. [DOI: 10.1063/1.5009908] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Ty Faulkner
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia 22807, USA
| | - Isaac Miller
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia 22807, USA
| | - Paul L. Raston
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia 22807, USA
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11
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Hou D, Zhang XL, Zhai Y, Li H. The Role of High Excitations in Constructing Sub-spectroscopic Accuracy Intermolecular Potential of He-HCN: Critically Examined by the High-Resolution Spectra with Resonance States. CHINESE J CHEM PHYS 2017. [DOI: 10.1063/1674-0068/30/cjcp1712231] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Dan Hou
- Institute of Functional Materials and Agricultural Applied Chemistry, College of Science, Jiangxi Agricultural University, Nanchang 330045, China
| | - Xiao-Long Zhang
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China
| | - Yu Zhai
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China
| | - Hui Li
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China
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12
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Wang Z, Feng E, Zhang C, Sun C. The first potential energy surface and microwave spectra of the Hg–CO 2 complex. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.10.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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13
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Liu JM, Zhai Y, Li H. Explicit correlation treatment of the six-dimensional potential energy surface and predicted infrared spectra for OCS–H2. J Chem Phys 2017; 147:044313. [DOI: 10.1063/1.4996086] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Jing-Min Liu
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130023, People’s Republic of China
| | - Yu Zhai
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130023, People’s Republic of China
| | - Hui Li
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130023, People’s Republic of China
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14
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Wang Z, Feng E, Zhang C, Sun C. The potential energy surface and infrared spectra of the Ar–C 2 H 2 complex. COMPUT THEOR CHEM 2017. [DOI: 10.1016/j.comptc.2017.04.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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15
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Xue RJ, Grofe A, Yin H, Qu Z, Gao J, Li H. Perturbation Approach for Computing Infrared Spectra of the Local Mode of Probe Molecules. J Chem Theory Comput 2017; 13:191-201. [PMID: 28068771 DOI: 10.1021/acs.jctc.6b00733] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Linear and two-dimensional infrared (IR) spectroscopy of site-specific probe molecules provides an opportunity to gain a molecular-level understanding of the local hydrogen-bonding network, conformational dynamics, and long-range electrostatic interactions in condensed-phase and biological systems. A challenge in computation is to determine the time-dependent vibrational frequencies that incorporate explicitly both nuclear quantum effects of vibrational motions and an electronic structural representation of the potential energy surface. In this paper, a nuclear quantum vibrational perturbation (QVP) method is described for efficiently determining the instantaneous vibrational frequency of a chromophore in molecular dynamics simulations. Computational efficiency is achieved through the use of (a) discrete variable representation of the vibrational wave functions, (b) a perturbation theory to evaluate the vibrational energy shifts due to solvent dynamic fluctuations, and (c) a combined QM/MM potential for the systems. It was found that first-order perturbation is sufficiently accurate, enabling time-dependent vibrational frequencies to be obtained on the fly in molecular dynamics. The QVP method is illustrated in the mode-specific linear and 2D-IR spectra of the H-Cl stretching frequency in the HCl-water clusters and the carbonyl stretching vibration of acetone in aqueous solution. To further reduce computational cost, a hybrid strategy was proposed, and it was found that the computed vibrational spectral peak position and line shape are in agreement with experimental results. In addition, it was found that anharmonicity is significant in the H-Cl stretching mode, and hydrogen-bonding interactions further enhance anharmonic effects. The present QVP method complements other computational approaches, including path integral-based molecular dynamics, and represents a major improvement over the electrostatics-based spectroscopic mapping procedures.
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Affiliation(s)
- Rui-Jie Xue
- Institute of Theoretical Chemistry, Jilin University , 2519 Jiefang Road, Changchun 130023, People's Republic of China
| | - Adam Grofe
- Department of Chemistry and Supercomputing Institute, University of Minnesota , 207 Pleasant Street, SE, Minneapolis, Minnesota 55455, United States
| | - He Yin
- Institute of Theoretical Chemistry, Jilin University , 2519 Jiefang Road, Changchun 130023, People's Republic of China
| | - Zexing Qu
- Institute of Theoretical Chemistry, Jilin University , 2519 Jiefang Road, Changchun 130023, People's Republic of China
| | - Jiali Gao
- Institute of Theoretical Chemistry, Jilin University , 2519 Jiefang Road, Changchun 130023, People's Republic of China.,Department of Chemistry and Supercomputing Institute, University of Minnesota , 207 Pleasant Street, SE, Minneapolis, Minnesota 55455, United States
| | - Hui Li
- Institute of Theoretical Chemistry, Jilin University , 2519 Jiefang Road, Changchun 130023, People's Republic of China
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16
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17
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Hou D, Ma YT, Zhang XL, Li H. The origins of intra- and inter-molecular vibrational couplings: A case study of H2O-Ar on full and reduced-dimensional potential energy surface. J Chem Phys 2016; 144:014301. [DOI: 10.1063/1.4939089] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Dan Hou
- Institute of Theoretical Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130023, People’s Republic of China
| | - Yong-Tao Ma
- Institute of Theoretical Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130023, People’s Republic of China
| | - Xiao-Long Zhang
- Institute of Theoretical Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130023, People’s Republic of China
| | - Hui Li
- Institute of Theoretical Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130023, People’s Republic of China
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18
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Valdés Á, Prosmiti R. Vibrational Calculations of Higher-Order Weakly Bound Complexes: The He3,4I2 Cases. J Phys Chem A 2015; 119:12736-41. [PMID: 26634405 DOI: 10.1021/acs.jpca.5b10398] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The structure and relative stability of higher-order He3,4I2 clusters are investigated by carrying out full-dimensional quantum calculations within the multiconfiguration time-dependent Hartree framework. The full interaction between the I2 molecule and the He atoms is based on analytical three-body ab initio He-I2 potentials obtained from high level ab initio calculations plus the He-He interaction. The low-lying minima on the potential surfaces are found to be very close in energy with the He atoms in a ring encircling the dopant for the global minimum structure, while for the local minima one or two of the He atoms prefer the linear arrangements along the I2-axis. Such classical description on the basis of the potential energy landscape is corrected by including anharmonic quantum effects, present in highly floppy systems, by carrying out full dimensional quantum calculations. The potential energy operator was constructed by natural potential fits, while a mode combination scheme was employed to optimize the computational cost of the improved relaxation calculations. The obtained results predict the relative stability of the He3,4I2 isomers at zero temperature and provide benchmark data on binding energies and structural properties of these van der Waals systems. The (2,1) and (2,2), involving two He atoms in the T-shape and one or two He atoms in the linear configurations, respectively, are found to be the most stable isomers, although extremely close in energy with the (3,0) and (4,0) ones as predicted by classical optimizations. Comparison with experimental data on similar systems at low temperatures is also discussed. This analysis indicates once more the importance of quantum delocalization and the need of accurate quantum-mechanical treatments to characterize such doped helium nanosystems.
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Affiliation(s)
- Álvaro Valdés
- Departamento de Física, Universidad Nacional de Colombia , Calle 26, Cra 39, Edificio 404, Bogotá, Colombia
| | - Rita Prosmiti
- Instituto de Física Fundamental (IFF-CSIC), CSIC , Serrano 123, 28006 Madrid, Spain
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19
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Shang J, Yuan T, Zhu H. A new four-dimensional ab initio potential energy surface and predicted infrared spectra for the He–CS2 complex. Theor Chem Acc 2015. [DOI: 10.1007/s00214-015-1755-y] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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20
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Schmidt M, Fernández JM, Faruk N, Nooijen M, Le Roy RJ, Morilla JH, Tejeda G, Montero S, Roy PN. Raman Vibrational Shifts of Small Clusters of Hydrogen Isotopologues. J Phys Chem A 2015; 119:12551-61. [DOI: 10.1021/acs.jpca.5b08852] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Matthew Schmidt
- Department
of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
| | - José M. Fernández
- Laboratory
of Molecular Fluid Dynamics, Instituto de Estructura de la Materia, CSIC, Serrano 121, E-28006 Madrid, Spain
| | - Nabil Faruk
- Department
of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
| | - Marcel Nooijen
- Department
of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
| | - Robert J. Le Roy
- Department
of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
| | - Juan H. Morilla
- Laboratory
of Molecular Fluid Dynamics, Instituto de Estructura de la Materia, CSIC, Serrano 121, E-28006 Madrid, Spain
| | - Guzmán Tejeda
- Laboratory
of Molecular Fluid Dynamics, Instituto de Estructura de la Materia, CSIC, Serrano 121, E-28006 Madrid, Spain
| | - Salvador Montero
- Laboratory
of Molecular Fluid Dynamics, Instituto de Estructura de la Materia, CSIC, Serrano 121, E-28006 Madrid, Spain
| | - Pierre-Nicholas Roy
- Department
of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
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21
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22
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Yuan T, Sun X, Hu Y, Zhu H. A new ab initio potential energy surface and infrared spectra for the Ar-CS₂ complex. J Chem Phys 2014; 141:104306. [PMID: 25217915 DOI: 10.1063/1.4894504] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report a new three-dimensional potential energy surface for Ar-CS2 involving the Q3 normal mode for the υ3 antisymmetric stretching vibration of the CS2 molecule. The potential energies were calculated using the supermolecular method at the coupled-cluster singles and doubles level with noniterative inclusion of connected triples, using augmented correlation-consistent quadruple-zeta basis set plus midpoint bond functions. Two vibrationally averaged potentials with CS2 at both the ground (υ = 0) and the first excited (υ = 1)υ3 vibrational states were generated from the integration of the three-dimensional potential over the Q3 coordinate. Each potential was found to have a T-shaped global minimum and two equivalent linear local minima. The radial discrete variable representation /angular finite basis representation method and the Lanczos algorithm were applied to calculate the rovibrational energy levels. The calculated band origin shift of the complex (0.0622 cm(-1)) is very close to the observed one (0.0671 cm(-1)). The predicted infrared spectra and spectroscopic parameters based on the two averaged potentials are in excellent agreement with the available experimental data.
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Affiliation(s)
- Ting Yuan
- School of Chemistry, Sichuan University, Chengdu 610064, China and State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610064, China
| | - Xueli Sun
- School of Chemistry, Sichuan University, Chengdu 610064, China and State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610064, China
| | - Yi Hu
- School of Chemistry, Sichuan University, Chengdu 610064, China and State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610064, China
| | - Hua Zhu
- School of Chemistry, Sichuan University, Chengdu 610064, China and State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610064, China
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23
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Pérez de Tudela R, Barragán P, Valdés Á, Prosmiti R. Energetics and solvation structure of a dihalogen dopant (I2) in (4)He clusters. J Phys Chem A 2014; 118:6492-500. [PMID: 24869502 DOI: 10.1021/jp502994g] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The energetics and structure of small HeNI2 clusters are analyzed as the size of the system changes, with N up to 38. The full interaction between the I2 molecule and the He atoms is based on analytical ab initio He-I2 potentials plus the He-He interaction, obtained from first-principle calculations. The most stable structures, as a function of the number of solvent He atoms, are obtained by employing an evolutionary algorithm and compared with CCSD(T) and MP2 ab initio computations. Further, the classical description is completed by explicitly including thermal corrections and quantum features, such as zero-point-energy values and spatial delocalization. From quantum PIMC calculations, the binding energies and radial/angular probability density distributions of the thermal equilibrium state for selected-size clusters are computed at a low temperature. The sequential formation of regular shell structures is analyzed and discussed for both classical and quantum treatments.
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24
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Faruk N, Schmidt M, Li H, Le Roy RJ, Roy PN. First-principles prediction of the Raman shifts in parahydrogen clusters. J Chem Phys 2014; 141:014310. [DOI: 10.1063/1.4885275] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Nabil Faruk
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Matthew Schmidt
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Hui Li
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
- Institute of Theoretical Chemistry, State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130023, People's Republic of China
| | - Robert J. Le Roy
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Pierre-Nicholas Roy
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
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25
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Ma YT, Zeng T, Li H. Analytical Morse/long-Range model potential and predicted infrared and microwave spectra for a symmetric top-atom dimer: A case study of CH3F–He. J Chem Phys 2014; 140:214309. [DOI: 10.1063/1.4879956] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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26
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Li H, Zhang XL, Le Roy RJ, Roy PN. Analytic Morse/long-range potential energy surfaces and predicted infrared spectra for CO–H2 dimer and frequency shifts of CO in (para-H2)N N = 1–20 clusters. J Chem Phys 2013; 139:164315. [DOI: 10.1063/1.4826595] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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27
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Sesé LM. Path integral Monte Carlo study of quantum-hard sphere solids. J Chem Phys 2013; 139:044502. [DOI: 10.1063/1.4813635] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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28
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Santamaria R, Bokhimi X, Soullard J, Jellinek J. Pressure-Induced Metallization of Li+-Doped Hydrogen Clusters. J Phys Chem A 2013; 117:5642-9. [DOI: 10.1021/jp400483z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Xim Bokhimi
- Instituto de Fı́sica, UNAM, A.P. 20-364, México D.F
| | | | - Julius Jellinek
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439,
United States
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29
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Tritzant-Martinez Y, Zeng T, Broom A, Meiering E, Le Roy RJ, Roy PN. On the analytical representation of free energy profiles with a Morse/long-range model: Application to the water dimer. J Chem Phys 2013; 138:234103. [DOI: 10.1063/1.4810006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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30
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Zeng T, Li H, Roy PN. Simulating Asymmetric Top Impurities in Superfluid Clusters: A para-Water Dopant in para-Hydrogen. J Phys Chem Lett 2013; 4:18-22. [PMID: 26291205 DOI: 10.1021/jz3017705] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We present the first simulation study of bosonic clusters doped with an asymmetric top molecule. The path-integral Monte Carlo method with the latest methodological advance in treating rigid-body rotation [Noya, E. G.; Vega, C.; McBride, C. J. Chem. Phys.2011, 134, 054117] is employed to study a para-water impurity in para-hydrogen clusters with up to 20 para-hydrogen molecules. The growth pattern of the doped clusters is similar in nature to that of pure clusters. The para-water molecule appears to rotate freely in the cluster. The presence of para-water substantially quenches the superfluid response of para-hydrogen with respect to the space-fixed frame.
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Affiliation(s)
- Tao Zeng
- †Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Hui Li
- ‡Institute of Theoretical Chemistry, State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130023, People's Republic of China
| | - Pierre-Nicholas Roy
- †Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
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31
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Li H, Ma YT. An intramolecular vibrationally excited intermolecular potential for He–OCS: Globally tested by simulation of vibrational shifts for OCS in HeN N = 1 − 100 Clusters. J Chem Phys 2012; 137:234310. [PMID: 23267489 DOI: 10.1063/1.4772186] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Affiliation(s)
- Hui Li
- Institute of Theoretical Chemistry, State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130023, People's Republic of China.
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32
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Wang L, Xie D, Le Roy RJ, Roy PN. A new four-dimensional ab initio potential energy surface for N2O-He and vibrational band origin shifts for the N2O-He(N) clusters with N = 1-40. J Chem Phys 2012; 137:104311. [PMID: 22979863 DOI: 10.1063/1.4749248] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A new four-dimensional ab initio potential energy surface for N(2)O-He is constructed at the CCSD(T) level with an aug-cc-pVQZ basis set together with bond functions. The vibrational coordinates Q(1) and Q(3) of N(2)O are explicitly included, due to the strong coupling between the symmetric and asymmetric stretches of N(2)O. A global potential energy surface is obtained by fitting the original potential points to a four-dimensional Morse∕long range (MLR) analytical form. In the fitting, the ab initio noise in the long range region of the potential is smoothed over by theoretically fixed long range parameters. Two-dimensional intermolecular potentials for both the ground and the excited υ(3) states of N(2)O are then constructed by vibrationally averaging the four-dimensional potential. Based on the two-dimensional potentials, we use the path integral Monte Carlo algorithm to calculate the vibrational band origin shifts for the N(2)O-He(N) clusters using a first order perturbation theory estimate. The calculated shifts agree reasonably well with the experimental values and reproduce the evolution tendency from dimer to large clusters.
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Affiliation(s)
- Lecheng Wang
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
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33
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Wang L, Xie D. Finite temperature path integral Monte Carlo simulations of structural and dynamical properties of ArN−CO2 clusters. J Chem Phys 2012; 137:074308. [DOI: 10.1063/1.4746941] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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34
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Raston PL, Jäger W, Li H, Le Roy RJ, Roy PN. Persistent molecular superfluid response in doped para-hydrogen clusters. PHYSICAL REVIEW LETTERS 2012; 108:253402. [PMID: 23004599 DOI: 10.1103/physrevlett.108.253402] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2011] [Indexed: 06/01/2023]
Abstract
Direct observation of superfluid response in para-hydrogen (p-H(2)) remains a challenge because of the need for a probe that would not induce localization and a resultant reduction in superfluid fraction. Earlier work [H. Li, R. J. Le Roy, P.-N. Roy, and A. R. W. McKellar, Phys. Rev. Lett. 105, 133401 (2010)] has shown that carbon dioxide can probe the effective inertia of p-H(2) although larger clusters show a lower superfluid response due to localization. It is shown here that the lighter carbon monoxide probe molecule allows one to measure the effective inertia of p-H(2) clusters while maintaining a maximum superfluid response with respect to dopant rotation. Microwave spectroscopy and a theoretical analysis based on Feynman path-integral simulations are used to support this conclusion.
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Affiliation(s)
- P L Raston
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
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35
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Ing C, Hinsen K, Yang J, Zeng T, Li H, Roy PN. A path-integral Langevin equation treatment of low-temperature doped helium clusters. J Chem Phys 2012; 136:224309. [DOI: 10.1063/1.4726507] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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36
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Affiliation(s)
- Brian M. Austin
- Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, University of California at Berkeley, Berkeley, California 94720, United States
| | - Dmitry Yu. Zubarev
- Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, University of California at Berkeley, Berkeley, California 94720, United States
| | - William A. Lester
- Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, University of California at Berkeley, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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37
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McKellar ARW, Mizoguchi A, Kanamori H. High resolution quantum cascade laser studies of the ν3 band of methyl fluoride in solid para-hydrogen. J Chem Phys 2011; 135:124511. [PMID: 21974539 DOI: 10.1063/1.3640888] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Spectra of solid para-H(2) doped with CH(3)F at 1.8 K are studied in the ν(3) region (~1040 cm(-1)) using a quantum cascade laser source. As shown previously, residual ortho-H(2) in the sample (~1000 ppm) gives rise to distinct spectral features due to clusters of the form CH(3)F-(ortho-H(2))(N), with N = 0, 1, 2, 3, etc. Brief annealing at 7 K is found to give narrower spectral lines (≥0.006 cm(-1)) than conventional (5 K) annealing, and causes the N = 3 and 4 lines to fragment into two or more components. The N = 3 line is observed to be particularly stable and persistent. The N = 0 line (no ortho-H(2) neighbors) is resolved into two closely spaced (≈0.007 cm(-1)) components which are assigned to the K = 0 and 1 states of CH(3)F rotating around its C(3v) symmetry axis (ortho- and para-CH(3)F, respectively). Similar K-structure is also evident for other lines. Weak but persistent features ("N = 1/2 lines") are observed mid way between N = 0 and 1.
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Affiliation(s)
- A R W McKellar
- Department of Physics, Tokyo Institute of Technology, Ohokayama 2-12-1, Tokyo 152-8551, Japan.
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38
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Chen R, Zhu H, Xie D. Intermolecular potential energy surface, microwave and infrared spectra of the Kr–CO2 complex from ab initio calculations. Chem Phys Lett 2011. [DOI: 10.1016/j.cplett.2011.06.067] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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39
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Li H, McKellar ARW, Le Roy RJ, Roy PN. Theoretical and experimental study of weakly bound CO2-(pH2)2 trimers. J Phys Chem A 2011; 115:7327-37. [PMID: 21627164 DOI: 10.1021/jp200810f] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The infrared spectrum of CO(2)-(pH(2))(2) trimers is predicted by performing exact basis-set calculations on a global potential energy surface defined as the sum of accurately known two-body pH(2)-CO(2) (J. Chem. Phys. 2010, 132, 214309) and pH(2)-pH(2) potentials (J. Chem. Phys. 2008, 129, 094304). These results are compared with new spectroscopic measurements for this species, for which 13 transitions are now assigned. A reduced-dimension treatment of the pH(2) rotation has been employed by applying the hindered-rotor averaging technique of Li, Roy, and Le Roy (J. Chem. Phys. 2010, 133, 104305). Three-body effects and the quality of the potential are discussed. A new technique for displaying the three-dimensional pH(2) density in the body-fixed frame is used, and shows that in the ground state the two pH(2) molecules are localized much more closely together than is the case for the two He atoms in the analogous CO(2)-(He)(2) species. A clear tunneling splitting is evident for the torsional motion of the two pH(2) molecules on a ring about the CO(2) molecular axis, in contrast to the case of CO(2)-(He)(2) where a more regular progression of vibrational levels reflects the much lower torsional barrier.
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Affiliation(s)
- Hui Li
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
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40
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Li H, Liu Y, Jäger W, Le Roy RJ, Roy PN. Theoretical study of the microwave spectrum of isotopologues of OCS–(He)2. CAN J CHEM 2010. [DOI: 10.1139/v10-116] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The rovibrational energy levels (J = 0–3) and rotational spectra of seven isotopologues of the OCS–(He)2 complex have been determined by numerically exact basis set calculations. The interaction energy is represented as a sum of two-body terms consisting of the OCS–He potential, which Howson and Hutson (J. Chem. Phys. 2001, 115, 5059) obtained at the CCSD(T)/aug-cc-pVTZ level of theory, and the He–He potential that Jeziorska et al. (J. Chem. Phys. 2007, 127,124303) obtained with SAPT theory. Three-body effects and the quality of the potential are discussed. Comparison with experiment shows that microwave transitions can be predicted by this additive approach with an accuracy equal or better than 0.7% for all the observed spectral lines. A method for the three-dimensional representation of the helium density in the body-fixed frame is presented that highlights the highly delocalized nature of the helium subsystem.
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Affiliation(s)
- Hui Li
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
- Institute of Theoretical Chemistry, State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130023, P.R. China
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | - Yongdong Liu
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
- Institute of Theoretical Chemistry, State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130023, P.R. China
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | - Wolfgang Jäger
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
- Institute of Theoretical Chemistry, State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130023, P.R. China
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | - Robert J. Le Roy
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
- Institute of Theoretical Chemistry, State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130023, P.R. China
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | - Pierre-Nicholas Roy
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
- Institute of Theoretical Chemistry, State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130023, P.R. China
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
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41
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Li H, Le Roy RJ, Roy PN, McKellar ARW. Molecular superfluid: nonclassical rotations in doped para-hydrogen clusters. PHYSICAL REVIEW LETTERS 2010; 105:133401. [PMID: 21230772 DOI: 10.1103/physrevlett.105.133401] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Indexed: 05/30/2023]
Abstract
Clusters of para-hydrogen (pH₂) have been predicted to exhibit superfluid behavior, but direct observation of this phenomenon has been elusive. Combining experiments and theoretical simulations, we have determined the size evolution of the superfluid response of pH₂ clusters doped with carbon dioxide (CO₂). Reduction of the effective inertia is observed when the dopant is surrounded by the pH₂ solvent. This marks the onset of molecular superfluidity in pH₂. The fractional occupation of solvation rings around CO₂ correlates with enhanced superfluid response for certain cluster sizes.
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Affiliation(s)
- Hui Li
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada
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42
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Abstract
We report calculated microwave and infrared rovibrational transitions of the van der Waals complex He2–OCS. The calculations were done using a product basis, a Lanczos eigensolver, and potentials built from He–OCS, and He–He potential functions taken from the literature. All five of the large amplitude coordinates are treated exactly and calculations are done for J values up to five. All rovibrational levels are converged to 0.001 cm–1 by using basis sets with as many as 87 million funcions. Good agreement is found with previously reported experimental results. Although we assume that the dipole moment is along the OCS axis, we find transitions with appreciable intensity between different torsion states.
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Affiliation(s)
- Xiao-Gang Wang
- Chemistry Department, Queen’s University, Kingston, ON K7L 3N6, Canada
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43
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Li H, Roy PN, Le Roy RJ. Analytic Morse/long-range potential energy surfaces and predicted infrared spectra for CO2–H2. J Chem Phys 2010; 132:214309. [DOI: 10.1063/1.3428619] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
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44
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de Lara-Castells MP, Aguirre NF, Villarreal P, Barrio GD, Mitrushchenkov AO. Quantum solvent states and rovibrational spectra of small doped H3e clusters through the full-configuration-interaction nuclear orbital approach: The (H3e)N–Cl2(X) case (N≤4). J Chem Phys 2010; 132:194313. [DOI: 10.1063/1.3425997] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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45
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Whitley HD, DuBois JL, Whaley KB. Spectral shifts and helium configurations in 4He(N)-tetracene clusters. J Chem Phys 2009; 131:124514. [PMID: 19791901 DOI: 10.1063/1.3236386] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Spectral shifts of electronic transitions of tetracene in helium droplets are investigated in a theoretical study of (4)He(N)-tetracene clusters with 1 < or = N < or = 150. Utilizing a pairwise interaction for the S(0) state of tetracene with helium that is extended by semiempirical terms to construct a potential for the S(1) state of tetracene with helium, the spectral shift is calculated from path integral Monte Carlo calculations of the helium equilibrium properties with tetracene in the S(0) and S(1) states at T = 0 and at T = 0.625 K. The calculated spectral shifts are in quantitative agreement with available experimental measurements for small values of N (< or = 8) at T approximately 0.4 K and show qualitative agreement for larger N (10-20). The extrapolated value of the spectral shift in large droplets (N approximately 10(4)) is approximately 90% of the experimentally measured value. We find no evidence of multiple configurations of helium for any cluster size for either the S(0) or S(1) state of tetracene. These results suggest that the observed spectral splitting of electronic transitions of tetracene in large helium droplets is not due to the coexistence of static metastable helium densities, unlike the situation previously analyzed for the phthalocyanine molecule.
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Affiliation(s)
- Heather D Whitley
- Department of Chemistry and Kenneth S. Pitzer Center for Theoretical Chemistry, University of California, Berkeley, California 94720, USA.
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46
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Wang XG, Carrington T, McKellar ARW. Theoretical and experimental study of the rovibrational spectrum of He(2)-CO. J Phys Chem A 2009; 113:13331-41. [PMID: 19842654 DOI: 10.1021/jp904778f] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report calculated microwave and infrared ro-vibrational transitions of the van der Waals complex He(2)-CO. The calculations were done using a product basis and a Lanczos eigensolver, together with He-CO and He-He potential functions taken from the literature. The results are found to be in good agreement with previously reported experimental results, and they enable the experimental assignments to be clarified, augmented, and (in one case) corrected. Unlike some other van der Waals complexes with two He atoms such as He(2)-N(2)O, it is not possible to associate a set of energy levels with the "torsional" motion of the two He atoms on a ring encircling the dopant (in this case CO). Although we assume that the dipole moment is along the CO axis we find nonetheless that many transitions have appreciable intensity due to ro-vibrational coupling.
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Affiliation(s)
- Xiao-Gang Wang
- Chemistry Department, Queen's University, Kingston, Ontario K7L 3N6, Canada
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47
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Cui Y, Ran H, Xie D. A new potential energy surface and predicted infrared spectra of the Ar-CO(2) van der Waals complex. J Chem Phys 2009; 130:224311. [PMID: 19530772 DOI: 10.1063/1.3152990] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A new potential energy surface for Ar-CO(2) is constructed at the coupled-cluster singles and doubles with noniterative inclusion of connected triple [CCSD(T)] level with augmented correlation-consistent triple-zeta (aug-cc-pVTZ) basis set plus midpoint bond functions. The Q(3) normal mode for the v(3) antisymmetric stretching vibration of CO(2) is involved in the construction of the potential. Effective two-dimensional potentials with CO(2) in the ground and first excited v(3) vibrational states are obtained by averaging a three-dimensional potential for each case over the Q(3) asymmetric stretch vibrational coordinate. Both potentials have only a T-shaped minimum with a well depth of 200.97 and 201.37 cm(-1), respectively. No linear local minima are detected. The radial discrete variable representation/angular finite basis representation method and the Lanczos algorithm are employed to calculate the related rovibrational energy levels. The calculated band origin shift of the complex agrees very well with the observed one (-0.474 versus -0.470 cm(-1)). In addition, the predicted infrared spectra based on the two averaged potentials are in excellent agreement with the available experimental data, which again testifies the accuracy of the new potentials.
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Affiliation(s)
- Yali Cui
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
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