51
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Schröder M, Meyer HD. Transforming high-dimensional potential energy surfaces into sum-of-products form using Monte Carlo methods. J Chem Phys 2017; 147:064105. [DOI: 10.1063/1.4991851] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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52
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Brown A, Pradhan E. Fitting potential energy surfaces to sum-of-products form with neural networks using exponential neurons. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2017. [DOI: 10.1142/s0219633617300014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In this paper, the use of the neural network (NN) method with exponential neurons for directly fitting ab initio data to generate potential energy surfaces (PESs) in sum-of-product form will be discussed. The utility of the approach will be highlighted using fits of CS2, HFCO, and HONO ground state PESs based upon high-level ab initio data. Using a generic interface between the neural network PES fitting, which is performed in MATLAB, and the Heidelberg multi-configuration time-dependent Hartree (MCTDH) software package, the PESs have been tested via comparison of vibrational energies to experimental measurements. The review demonstrates the potential of the PES fitting method, combined with MCTDH, to tackle high-dimensional quantum dynamics problems.
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Affiliation(s)
- Alex Brown
- Department of Chemistry, University of Alberta, Edmonton, AB, T6G 2G2, Canada
| | - E. Pradhan
- Department of Chemistry, University of Alberta, Edmonton, AB, T6G 2G2, Canada
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53
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Larsson HR, Tannor DJ. Dynamical pruning of the multiconfiguration time-dependent Hartree (DP-MCTDH) method: An efficient approach for multidimensional quantum dynamics. J Chem Phys 2017; 147:044103. [DOI: 10.1063/1.4993219] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- H. R. Larsson
- Institut für Physikalische Chemie, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
- Department of Chemical Physics, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - D. J. Tannor
- Department of Chemical Physics, Weizmann Institute of Science, 76100 Rehovot, Israel
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54
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Manthe U. Wavepacket dynamics and the multi-configurational time-dependent Hartree approach. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:253001. [PMID: 28430111 DOI: 10.1088/1361-648x/aa6e96] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Multi-configurational time-dependent Hartree (MCTDH) based approaches are efficient, accurate, and versatile methods for high-dimensional quantum dynamics simulations. Applications range from detailed investigations of polyatomic reaction processes in the gas phase to high-dimensional simulations studying the dynamics of condensed phase systems described by typical solid state physics model Hamiltonians. The present article presents an overview of the different areas of application and provides a comprehensive review of the underlying theory. The concepts and guiding ideas underlying the MCTDH approach and its multi-mode and multi-layer extensions are discussed in detail. The general structure of the equations of motion is highlighted. The representation of the Hamiltonian and the correlated discrete variable representation (CDVR), which provides an efficient multi-dimensional quadrature in MCTDH calculations, are discussed. Methods which facilitate the calculation of eigenstates, the evaluation of correlation functions, and the efficient representation of thermal ensembles in MCTDH calculations are described. Different schemes for the treatment of indistinguishable particles in MCTDH calculations and recent developments towards a unified multi-layer MCTDH theory for systems including bosons and fermions are discussed.
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Affiliation(s)
- Uwe Manthe
- Theoretische Chemie, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, D-33615 Bielefeld, Germany
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55
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Peláez D, Meyer HD. On the infrared absorption spectrum of the hydrated hydroxide (H3O2-) cluster anion. Chem Phys 2017. [DOI: 10.1016/j.chemphys.2016.08.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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56
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Pradhan E, Brown A. A ground state potential energy surface for HONO based on a neural network with exponential fitting functions. Phys Chem Chem Phys 2017; 19:22272-22281. [DOI: 10.1039/c7cp04010e] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Using CCSD(T)-F12/cc-pVTZ-F12 and CCSD(T)/CBS ab initio energies, two different six-dimensional ground state potential energy surfaces for HONO have been fit in sum-of-products form using neural network exponential fitting functions and tested by computing vibrational energies with MCTDH.
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Affiliation(s)
| | - Alex Brown
- Department of Chemistry
- University of Alberta
- Edmonton
- Canada
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57
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Larsson HR, Hartke B, Tannor DJ. Efficient molecular quantum dynamics in coordinate and phase space using pruned bases. J Chem Phys 2016; 145:204108. [DOI: 10.1063/1.4967432] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- H. R. Larsson
- Institut für Physikalische Chemie, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - B. Hartke
- Institut für Physikalische Chemie, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - D. J. Tannor
- Department of Chemical Physics, Weizmann Institute of Science, 76100 Rehovot, Israel
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58
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Zauleck JPP, Thallmair S, Loipersberger M, de Vivie-Riedle R. Two New Methods To Generate Internal Coordinates for Molecular Wave Packet Dynamics in Reduced Dimensions. J Chem Theory Comput 2016; 12:5698-5708. [PMID: 27951675 DOI: 10.1021/acs.jctc.6b00800] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The curse of dimensionality still remains as the central challenge of molecular quantum dynamical calculations. Either compromises on the accuracy of the potential landscape have to be made or methods must be used that reduce the dimensionality of the configuration space of molecular systems to a low dimensional one. For dynamic approaches such as grid-based wave packet dynamics that are confined to a small number of degrees of freedom this dimensionality reduction can become a major part of the overall problem. A common strategy to reduce the configuration space is by selection of a set of internal coordinates using chemical intuition. We devised two methods that increase the degree of automation of the dimensionality reduction as well as replace chemical intuition by more quantifiable criteria. Both methods reduce the dimensionality linearly and use the intrinsic reaction coordinate as guidance. The first one solely relies on the intrinsic reaction coordinate (IRC), whereas the second one uses semiclassical trajectories to identify the important degrees of freedom.
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Affiliation(s)
- Julius P P Zauleck
- Department Chemie, Ludwig-Maximilians-Universität München , D-81377 München, Germany
| | - Sebastian Thallmair
- Department Chemie, Ludwig-Maximilians-Universität München , D-81377 München, Germany
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59
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Brown J, Carrington T. Using an expanding nondirect product harmonic basis with an iterative eigensolver to compute vibrational energy levels with as many as seven atoms. J Chem Phys 2016; 145:144104. [DOI: 10.1063/1.4963916] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- James Brown
- Chemistry Department, Queen’s University, Kingston, Ontario K7L 3N6, Canada
| | - Tucker Carrington
- Chemistry Department, Queen’s University, Kingston, Ontario K7L 3N6, Canada
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60
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Wodraszka R, Carrington T. Using a pruned, nondirect product basis in conjunction with the multi-configuration time-dependent Hartree (MCTDH) method. J Chem Phys 2016; 145:044110. [DOI: 10.1063/1.4959228] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Robert Wodraszka
- Department of Chemistry, Queen’s University, Kingston, Ontario K7L 3N6, Canada
| | - Tucker Carrington
- Department of Chemistry, Queen’s University, Kingston, Ontario K7L 3N6, Canada
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61
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Dolbundalchok P, Peláez D, Aziz EF, Bande A. Geometrical control of the interatomic coulombic decay process in quantum dots for infrared photodetectors. J Comput Chem 2016; 37:2249-59. [PMID: 27452332 DOI: 10.1002/jcc.24410] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 04/24/2016] [Accepted: 05/02/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Praphasiri Dolbundalchok
- Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg; Im Neuenheimer Feld 229 Heidelberg 69120 Germany
| | - Daniel Peláez
- Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg; Im Neuenheimer Feld 229 Heidelberg 69120 Germany
- Laboratoire PhLAM - UFR Physique Bâtiment P5, Université Lille 1, 59655 Villeneuve dAscq Cedex, France
| | - Emad F. Aziz
- Institute of Methods for Material Development and Joint Ultrafast Dynamics Lab in Solutions and at Interfaces (JULiq), Helmholtz-Zentrum Berlin für Materialien und Energie GmbH; Albert-Einstein-Str. 15 12489 Berlin Germany
- Department of Physics; Freie Universit¨at Berlin; Arnimallee 14 14195 Berlin Germany
| | - Annika Bande
- Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg; Im Neuenheimer Feld 229 Heidelberg 69120 Germany
- Institute of Methods for Material Development and Joint Ultrafast Dynamics Lab in Solutions and at Interfaces (JULiq), Helmholtz-Zentrum Berlin für Materialien und Energie GmbH; Albert-Einstein-Str. 15 12489 Berlin Germany
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62
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Dawes R, Ndengué SA. Single- and multireference electronic structure calculations for constructing potential energy surfaces. INT REV PHYS CHEM 2016. [DOI: 10.1080/0144235x.2016.1195102] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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63
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Ziegler B, Rauhut G. Efficient generation of sum-of-products representations of high-dimensional potential energy surfaces based on multimode expansions. J Chem Phys 2016; 144:114114. [DOI: 10.1063/1.4943985] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Benjamin Ziegler
- Institut für Theoretische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Guntram Rauhut
- Institut für Theoretische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
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64
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Ansari N, Meyer HD. Isotope effects of ground and lowest lying vibrational states of H3−xDxO2− complexes. J Chem Phys 2016; 144:054308. [DOI: 10.1063/1.4940965] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Narjes Ansari
- Department of Chemistry, Institute for Advanced Studies in Basic Sciences, Zanjan 45137-66731, Iran
| | - Hans-Dieter Meyer
- Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg, Germany
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65
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Füchsel G, Thomas PS, den Uyl J, Öztürk Y, Nattino F, Meyer HD, Kroes GJ. Rotational effects on the dissociation dynamics of CHD3 on Pt(111). Phys Chem Chem Phys 2016; 18:8174-85. [DOI: 10.1039/c5cp07898a] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
MCTDH calculations suggest that experiments on the effect of alignment on dissociation of CH4 on metal surfaces are affected by steering.
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Affiliation(s)
- Gernot Füchsel
- Leiden Institute of Chemistry
- Gorlaeus Laboratories
- Leiden University
- 2300 RA Leiden
- The Netherlands
| | | | - Jurriaan den Uyl
- Leiden Institute of Chemistry
- Gorlaeus Laboratories
- Leiden University
- 2300 RA Leiden
- The Netherlands
| | - Yesim Öztürk
- Leiden Institute of Chemistry
- Gorlaeus Laboratories
- Leiden University
- 2300 RA Leiden
- The Netherlands
| | - Francesco Nattino
- Leiden Institute of Chemistry
- Gorlaeus Laboratories
- Leiden University
- 2300 RA Leiden
- The Netherlands
| | - Hans-Dieter Meyer
- Theoretische Chemie
- Physikalisch-Chemisches Institut
- Universität Heidelberg
- D-69120 Heidelberg
- Germany
| | - Geert-Jan Kroes
- Leiden Institute of Chemistry
- Gorlaeus Laboratories
- Leiden University
- 2300 RA Leiden
- The Netherlands
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66
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Baranov V, Oseledets I. Fitting high-dimensional potential energy surface using active subspace and tensor train (AS+TT) method. J Chem Phys 2015; 143:174107. [DOI: 10.1063/1.4935017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Vitaly Baranov
- Skolkovo Institute of Science and Technology, Novyaa St. 100, Skolkovo, Moscow 143025, Russia
| | - Ivan Oseledets
- Skolkovo Institute of Science and Technology, Novyaa St. 100, Skolkovo, Moscow 143025, Russia
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67
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Meng Q, Meyer HD. Expansion Hamiltonian model for a diatomic molecule adsorbed on a surface: Vibrational states of the CO/Cu(100) system including surface vibrations. J Chem Phys 2015; 143:164310. [DOI: 10.1063/1.4934506] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Affiliation(s)
- Qingyong Meng
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, 116023 Dalian, China
| | - Hans-Dieter Meyer
- Theoretische Chemie, Physikalisch-Chemisches Institut, Ruprecht-Karls Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg, Germany
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68
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69
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Yu HG, Ndengue S, Li J, Dawes R, Guo H. Vibrational energy levels of the simplest Criegee intermediate (CH2OO) from full-dimensional Lanczos, MCTDH, and MULTIMODE calculations. J Chem Phys 2015; 143:084311. [DOI: 10.1063/1.4929707] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Hua-Gen Yu
- Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Steve Ndengue
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, USA
| | - Jun Li
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - Richard Dawes
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, USA
| | - Hua Guo
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, USA
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70
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Avila G, Carrington T. Using multi-dimensional Smolyak interpolation to make a sum-of-products potential. J Chem Phys 2015; 143:044106. [DOI: 10.1063/1.4926651] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Gustavo Avila
- Chemistry Department, Queen’s University, Kingston, Ontario K7L 3N6, Canada
| | - Tucker Carrington
- Chemistry Department, Queen’s University, Kingston, Ontario K7L 3N6, Canada
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71
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Abstract
I review two new ideas for coping with the size of large product basis sets and large product grids when one computes vibrational energy levels. The first is based on a tensor reduction scheme. It exploits advantages of a sum-of-products potential. The key idea is to use a basis each of whose function is a sum of optimized products and to compress the number of terms in each basis function. When the potential does not have the sum-of-products form, it is usually necessary to use quadrature. The second idea uses a nondirect product grid that has structure and is therefore compatible with efficient matrix–vector products.
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Affiliation(s)
- Tucker Carrington
- Chemistry Department, Queen’s University, Kingston, ON K7L 3N6, Canada
- Chemistry Department, Queen’s University, Kingston, ON K7L 3N6, Canada
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72
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Sadri K, Lauvergnat D, Gatti F, Meyer HD. Rovibrational spectroscopy using a kinetic energy operator in Eckart frame and the multi-configuration time-dependent Hartree (MCTDH) approach. J Chem Phys 2014; 141:114101. [DOI: 10.1063/1.4895557] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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73
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Schröder M, Meyer HD. Calculation of the vibrational excited states of malonaldehyde and their tunneling splittings with the multi-configuration time-dependent Hartree method. J Chem Phys 2014; 141:034116. [DOI: 10.1063/1.4890116] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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74
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Koch W, Zhang DH. Communication: Separable potential energy surfaces from multiplicative artificial neural networks. J Chem Phys 2014; 141:021101. [DOI: 10.1063/1.4887508] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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75
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Leclerc A, Carrington T. Calculating vibrational spectra with sum of product basis functions without storing full-dimensional vectors or matrices. J Chem Phys 2014; 140:174111. [DOI: 10.1063/1.4871981] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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76
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Strobusch D, Scheurer C. Adaptive sparse grid expansions of the vibrational Hamiltonian. J Chem Phys 2014; 140:074111. [DOI: 10.1063/1.4864356] [Citation(s) in RCA: 12] [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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77
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Peláez D, Sadri K, Meyer HD. Full-dimensional MCTDH/MGPF study of the ground and lowest lying vibrational states of the bihydroxide H3O2(-) complex. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2014; 119:42-51. [PMID: 23831046 DOI: 10.1016/j.saa.2013.05.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 04/30/2013] [Accepted: 05/03/2013] [Indexed: 06/02/2023]
Abstract
In this study, we present a full-dimensional (9D) quantum dynamical analysis of the lowest vibrational eigenstates of H3O2(-). We have made use of the Multiconfiguration Time-Dependent Hartree method in conjunction with both an analytical and a numerical representation of the Kinetic Energy Operator and the newly developed Multigrid POTFIT [D. Peláez, H.-D. Meyer, J. Chem. Phys. 138 (2013) 014108], an algorithm which performs the transformation of a high-dimensional (up to ~12D) Potential Energy tensor into product form. Many sets of top-down Multigrid POTFIT expansions, differing in the system coordinate definition (valence and Jacobi), as well as in the number of terms in the expansion, have been analyzed. Relaxations for the computation of the ground states energies have been carried out on these potentials, obtaining an excellent overall agreement with accurate previous Diffusion Monte Carlo (DMC) calculations, irrespective of the coordinate choice. The 24 lowest excited vibrational states of H3O2(-) have been computed by Block Relaxation and assigned for the first time. This has been carried out in two different pictures, namely: a 7D reduced dimensional one, in which the OH distances have been frozen at the Potential Energy Surface minimum, and a 9D full-dimensional one. The agreement between both descriptions is remarkable. The following fundamental modes have been characterized: OH torsion, OO stretching, OH wagging, OH rocking, and the elusive bridging H stretching. In particular, we provide a very accurate description of the latter in perfect agreement with experiment.
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Affiliation(s)
- Daniel Peláez
- Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg, Germany.
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78
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Valdés Á, Prosmiti R. First-principles simulations of vibrational states and spectra for H5(+) and D5(+) clusters using multiconfiguration time-dependent Hartree approach. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2014; 119:26-33. [PMID: 23763866 DOI: 10.1016/j.saa.2013.05.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 05/06/2013] [Accepted: 05/12/2013] [Indexed: 06/02/2023]
Abstract
Simulations of the infrared (IR) spectra of the H5(+) and D5(+) clusters are carried out in the whole energy range, using a recent, reliable "on the fly" DFT-based potential energy surface, and its corresponding dipole moment surface. For the present study we adopted a recently proposed four-dimensional quantum model to describe the proton transfer motion between the two vibrating H2 or D2 units. Time-dependent and time-independent approaches within the multiconfiguration time-dependent Hartree method are employed for investigating the vibrational dynamics of the complexes. The obtained spectra are compared with recent experimental data available for energies up to 4500 and 3500 cm(-1) for the H5(+) and D5(+), respectively. Even though the present results are based on a reduced dimensional model, the infrared spectra are shown to be in good qualitative accord with those observed experimentally. Also as the reported data are subject to the potential energy surface, comparisons with previous theoretical calculations based on an analytical ab initio parameterized surface are also presented. The differences on the topology of the potentials are discussed in connection with their effect on the spectral features. We found that the main characteristics of the experimentally observed spectra are reproduced by both surfaces, evaluating in this way the sensitivity of such computations on the quality of the underlying potential. This finding serves to connect aspects of the potential surface of these systems to their spectral complexity, and could be indicative to calibrate intrinsic errors in their calculation for future studies.
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Affiliation(s)
- Álvaro Valdés
- Instituto de Física Fundamental, IFF-CSIC, Serrano 123, 28006 Madrid, Spain
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79
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Otto F. Multi-layer Potfit: An accurate potential representation for efficient high-dimensional quantum dynamics. J Chem Phys 2014; 140:014106. [DOI: 10.1063/1.4856135] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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80
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Meng Q, Meyer HD. MCTDH study on vibrational states of the CO/Cu(100) system. J Chem Phys 2013; 139:164709. [DOI: 10.1063/1.4826258] [Citation(s) in RCA: 10] [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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