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Ellerbrock R, Johnson KG, Seritan S, Hoppe H, Zhang JH, Lenzen T, Weike T, Manthe U, Martínez TJ. QuTree: A tree tensor network package. J Chem Phys 2024; 160:112501. [PMID: 38497471 DOI: 10.1063/5.0180233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Accepted: 02/20/2024] [Indexed: 03/19/2024] Open
Abstract
We present QuTree, a C++ library for tree tensor network approaches. QuTree provides class structures for tensors, tensor trees, and related linear algebra functions that facilitate the fast development of tree tensor network approaches such as the multilayer multiconfigurational time-dependent Hartree approach or the density matrix renormalization group approach and its various extensions. We investigate the efficiency of relevant tensor and tensor network operations and show that the overhead for managing the network structure is negligible, even in cases with a million leaves and small tensors. QuTree focuses on providing simple, high-level routines while retaining easy access to the backend to facilitate novel developments. We demonstrate the capabilities of the package by computing the eigenstates of coupled harmonic oscillator Hamiltonians and performing random circuit simulations on a virtual quantum computer.
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Affiliation(s)
- Roman Ellerbrock
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, USA
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
- Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - K Grace Johnson
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, USA
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Stefan Seritan
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, USA
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Hannes Hoppe
- Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - J H Zhang
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, USA
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Tim Lenzen
- Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Thomas Weike
- Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Uwe Manthe
- Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Todd J Martínez
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, USA
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
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2
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Hoppe H, Manthe U. Eigenstate calculation in the state-averaged (multi-layer) multi-configurational time-dependent Hartree approach. J Chem Phys 2024; 160:034104. [PMID: 38230812 DOI: 10.1063/5.0188748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 12/15/2023] [Indexed: 01/18/2024] Open
Abstract
A new approach for the calculation of eigenstates with the state-averaged (multi-layer) multi-configurational time-dependent Hartree (MCTDH) approach is presented. The approach is inspired by the recent work of Larsson [J. Chem. Phys. 151, 204102 (2019)]. It employs local optimization of the basis sets at each node of the multi-layer MCTDH tree and successive downward and upward sweeps to obtain a globally converged result. At the top node, the Hamiltonian represented in the basis of the single-particle functions (SPFs) of the first layer is diagonalized. Here p wavefunctions corresponding to the p lowest eigenvalues are computed by a block Lanczos approach. At all other nodes, a non-linear operator consisting of the respective mean-field Hamiltonian matrix and a projector onto the space spanned by the respective SPFs is considered. Here, the eigenstate corresponding to the lowest eigenvalue is computed using a short iterative Lanczos scheme. Two different examples are studied to illustrate the new approach: the calculation of the vibrational states of methyl and acetonitrile. The calculations for methyl employ the single-layer MCTDH approach, a general potential energy surface, and the correlation discrete variable representation. A five-layer MCTDH representation and a sum of product-type Hamiltonian are used in the acetonitrile calculations. Very fast convergence and order of magnitude reductions in the numerical effort compared to the previously used block relaxation scheme are found. Furthermore, a detailed comparison with the results of Avila and Carrington [J. Chem. Phys. 134, 054126 (2011)] for acetonitrile highlights the potential problems of convergence tests for high-dimensional systems.
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Affiliation(s)
- Hannes Hoppe
- Theoretische Chemie, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, D-33615 Bielefeld, Germany
| | - Uwe Manthe
- Theoretische Chemie, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, D-33615 Bielefeld, Germany
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Tan JA, Barbarona RF, Kuo JL. Approaching the "Zundel" Limit: Tuning the Vibrational Coupling in N 2H +Ng, Ng = {He, Ne, Ar, Kr, Xe, and Rn}. J Phys Chem A 2023. [PMID: 37418837 DOI: 10.1021/acs.jpca.3c01956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/09/2023]
Abstract
The diazenylium ion (N2H+) is a ubiquitous ion in dense molecular clouds. This ion is often used as a dense gas tracer in outer space. Most of the previous works on diazenylium ion have focused on the shared-proton stretch band, νH+. In this work, we have performed reduced-dimensional calculations to investigate the vibrational structure of N2H+Ng, Ng = {He, Ne, Ar, Kr, Xe, and Rn}. We demonstrate a few interesting things about this system. First, the vibrational coupling in N2H+ can be tuned to switch on interesting anharmonic effects such as Fermi resonance or combination bands by tagging it with different noble gases. Second, a comparison of the vibrational spectrum from N2H+He to N2H+Rn shows that the νH+ can be swept from an "Eigen-like" to a "Zundel-like" limiting case. Anharmonic calculations were performed using a multilevel approach, which utilized the MP2 and CCSD(T) levels of theories. Binding energies for the elimination of Ng in N2H+Ng are also reported.
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Affiliation(s)
- Jake A Tan
- Institute of Atomic and Molecular Science, Academia Sinica, Taipei 10617, Taiwan
| | - Rona F Barbarona
- Institute of Atomic and Molecular Science, Academia Sinica, Taipei 10617, Taiwan
- Molecular Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan
- Department of Physics, National Central University, Taoyuan 32001, Taiwan
| | - Jer-Lai Kuo
- Institute of Atomic and Molecular Science, Academia Sinica, Taipei 10617, Taiwan
- Molecular Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan
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Mendive-Tapia D, Meyer HD, Vendrell O. Optimal Mode Combination in the Multiconfiguration Time-Dependent Hartree Method through Multivariate Statistics: Factor Analysis and Hierarchical Clustering. J Chem Theory Comput 2023; 19:1144-1156. [PMID: 36716214 DOI: 10.1021/acs.jctc.2c01089] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The multiconfiguration time-dependent Hartree (MCTDH) method and its multilayer extension (ML-MCTDH) are powerful algorithms for the efficient computation of nuclear quantum dynamics in high-dimensional systems. By providing time-dependent variational orbitals and an optimal choice of layered effective degrees of freedom, one is able to reduce the computational cost to an amenable number of configurations. However, choices related to selecting properly the mode grouping and tensor tree are strongly system dependent and, thus far, subjectively based on intuition and/or experience. Therefore, herein we detail a new protocol based on multivariate statistics─more specifically, factor analysis and hierarchical clustering─for a reliable and convenient guiding in the optimal design of such complex "system-of-systems" tensor-network decompositions. The advantages of employing the new algorithm and its applicability are tested on water and two floppy protonated water clusters with large amplitude motions.
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Affiliation(s)
- David Mendive-Tapia
- Theoretische Chemie, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120Heidelberg, Germany
| | - Hans-Dieter Meyer
- Theoretische Chemie, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120Heidelberg, Germany
| | - Oriol Vendrell
- Theoretische Chemie, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120Heidelberg, Germany
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Tan JA, Takahashi K. Vibrational spectrum of a 1D oscillator: The quantum, the Wigner, and the classical ways. J CHIN CHEM SOC-TAIP 2022. [DOI: 10.1002/jccs.202200398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Jake A. Tan
- Institute of Atomic and Molecular Sciences Academia Sinica Taipei Taiwan
| | - Kaito Takahashi
- Institute of Atomic and Molecular Sciences Academia Sinica Taipei Taiwan
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The coupling of the hydrated proton to its first solvation shell. Nat Commun 2022; 13:6170. [PMID: 36257946 PMCID: PMC9579203 DOI: 10.1038/s41467-022-33650-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Accepted: 09/28/2022] [Indexed: 11/30/2022] Open
Abstract
The Zundel (\documentclass[12pt]{minimal}
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\begin{document}$${H}_{5}{O}_{2}^{+}$$\end{document}H5O2+) and Eigen (\documentclass[12pt]{minimal}
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\begin{document}$${H}_{9}{O}_{4}^{+}$$\end{document}H9O4+) cations play an important role as intermediate structures for proton transfer processes in liquid water. In the gas phase they exhibit radically different infrared (IR) spectra. The question arises: is there a least common denominator structure that explains the IR spectra of both, the Zundel and Eigen cations, and hence of the solvated proton? Full dimensional quantum simulations of these protonated cations demonstrate that two dynamical water molecules and an excess proton constitute this fundamental subunit. Embedded in the static environment of the parent Eigen cation, this subunit reproduces the positions and broadenings of its main excess-proton bands. In isolation, its spectrum reverts to the well-known Zundel ion. Hence, the dynamics of this subunit polarized by an environment suffice to explain the spectral signatures and anharmonic couplings of the solvated proton in its first solvation shell. The Zundel [H(H2O)2]+ and Eigen [H(H2O)4]+ cations exhibit radicallly different infrared spectra and are the limiting dynamical structures involved in proton mobility in liquid water. Here, the authors find through quantum dynamics simulations that two polarized water molecules and a proton suffice to explain the key spectroscopic features connected to proton mobility for both species.
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Larsson HR, Schröder M, Beckmann R, Brieuc F, Schran C, Marx D, Vendrell O. State-resolved infrared spectrum of the protonated water dimer: revisiting the characteristic proton transfer doublet peak. Chem Sci 2022; 13:11119-11125. [PMID: 36320484 PMCID: PMC9517273 DOI: 10.1039/d2sc03189b] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 08/26/2022] [Indexed: 11/29/2023] Open
Abstract
The infrared (IR) spectra of protonated water clusters encode precise information on the dynamics and structure of the hydrated proton. However, the strong anharmonic coupling and quantum effects of these elusive species remain puzzling up to the present day. Here, we report unequivocal evidence that the interplay between the proton transfer and the water wagging motions in the protonated water dimer (Zundel ion) giving rise to the characteristic doublet peak is both more complex and more sensitive to subtle energetic changes than previously thought. In particular, hitherto overlooked low-intensity satellite peaks in the experimental spectrum are now unveiled and mechanistically assigned. Our findings rely on the comparison of IR spectra obtained using two highly accurate potential energy surfaces in conjunction with highly accurate state-resolved quantum simulations. We demonstrate that these high-accuracy simulations are important for providing definite assignments of the complex IR signals of fluxional molecules.
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Affiliation(s)
- Henrik R Larsson
- Department of Chemistry and Biochemistry, University of California Merced CA 95343 USA
- Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena CA 91125 USA
| | - Markus Schröder
- Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg Im Neuenheimer Feld 229 D - 69120 Heidelberg Germany
| | - Richard Beckmann
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum 44780 Bochum Germany
| | - Fabien Brieuc
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum 44780 Bochum Germany
| | - Christoph Schran
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum 44780 Bochum Germany
| | - Dominik Marx
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum 44780 Bochum Germany
| | - Oriol Vendrell
- Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg Im Neuenheimer Feld 229 D - 69120 Heidelberg Germany
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Aerts A, Schaefer MR, Brown A. Adaptive Fitting of Potential Energy Surfaces of Small to Medium-Sized Molecules in Sum-of-Product Form: Application to Vibrational Spectroscopy. J Chem Phys 2022; 156:164106. [DOI: 10.1063/5.0089570] [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
A semi-automatic sampling and fitting procedure for generating sum-of-product (Born-Oppenheimer) potential energy surfaces based on a high-dimensional model representation is presented. The adaptive sampling procedure and subsequent fitting relies on energies only and can be used for re-fitting existing analytic potential energy surfaces in sum-of-product form or for direct fits from ab initio computa- tions. The method is tested by fitting ground electronic state potential energy surfaces for small to medium sized semi-rigid molecules, i.e., HFCO, HONO, and HCOOH, based upon ab initio computations at the CCSD(T)-F12/cc-pVTZ-F12 or MP2/aug-cc-pVTZ levels of theory. Vibrational eigenstates are computed using block improved relaxation in the Heidelberg MCTDH package and compared to available experimental and theoretical data. The new potential energy surfaces are compared to the best ones currently available for these molecules, in terms of accuracy, including of resulting vibrational states, required numbers of sampling points, and number of fitting parameters. The present procedure leads to compact expansions and scales well with the number of dimensions for simple potentials such as single or double wells.
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Affiliation(s)
| | | | - Alex Brown
- Department of Chemistry, University of Alberta, Canada
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Ellerbrock R, Manthe U. A non-hierarchical correlation discrete variable representation. J Chem Phys 2022; 156:134107. [PMID: 35395891 DOI: 10.1063/5.0088509] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The correlation discrete variable representation (CDVR) facilitates (multi-layer) multi-configurational time-dependent Hartree (MCTDH) calculations with general potentials. It employs a layered grid representation to efficiently evaluate all potential matrix elements appearing in the MCTDH equations of motion. The original CDVR approach and its multi-layer extension show a hierarchical structure: the size of the grids employed at the different layers increases when moving from an upper layer to a lower one. In this work, a non-hierarchical CDVR approach, which uses identically structured quadratures at all layers of the MCTDH wavefunction representation, is introduced. The non-hierarchical CDVR approach crucially reduces the number of grid points required, compared to the hierarchical CDVR, shows superior scaling properties, and yields identical results for all three representations showing the same topology. Numerical tests studying the photodissociation of NOCl and the vibrational states of CH3 demonstrate the accuracy of the non-hierarchical CDVR approach.
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Affiliation(s)
- Roman Ellerbrock
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, USA
| | - Uwe Manthe
- Theoretische Chemie, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, D-33615 Bielefeld, Germany
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Lindoy LP, Kloss B, Reichman DR. Time evolution of ML-MCTDH wavefunctions. II. Application of the projector splitting integrator. J Chem Phys 2021; 155:174109. [PMID: 34742222 DOI: 10.1063/5.0070043] [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 multi-layer multi-configuration time-dependent Hartree (ML-MCTDH) approach can suffer from numerical instabilities whenever the wavefunction is weakly entangled. These instabilities arise from singularities in the equations of motion (EOMs) and necessitate the use of regularization of the EOMs. The Projector Splitting Integrator (PSI) has previously been presented as an approach for evolving ML-MCTDH wavefunctions that is free of singularities. Here, we will discuss the implementation of the multi-layer PSI with a particular focus on how the steps required relate to those required to implement standard ML-MCTDH. We demonstrate the efficiency and stability of the PSI for large ML-MCTDH wavefunctions containing up to hundreds of thousands of nodes by considering a series of spin-boson models with up to 106 bath modes and find that for these problems, the PSI requires roughly 3-4 orders of magnitude fewer Hamiltonian evaluations and 2-3 orders of magnitude fewer Hamiltonian applications than standard ML-MCTDH and 2-3/1-2 orders of magnitude fewer evaluations/applications than approaches that use improved regularization schemes. Finally, we consider a series of significantly more challenging multi-spin-boson models that require much larger numbers of single-particle functions with wavefunctions containing up to ∼1.3×109 parameters to obtain accurate dynamics.
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Affiliation(s)
- Lachlan P Lindoy
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA
| | - Benedikt Kloss
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA
| | - David R Reichman
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA
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Lindoy LP, Kloss B, Reichman DR. Time evolution of ML-MCTDH wavefunctions. I. Gauge conditions, basis functions, and singularities. J Chem Phys 2021; 155:174108. [PMID: 34742180 DOI: 10.1063/5.0070042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
We derive a family of equations-of-motion (EOMs) for evolving multi-layer multiconfiguration time-dependent Hartree (ML-MCTDH) wavefunctions that, unlike the standard ML-MCTDH EOMs, never require the evaluation of the inverse of singular matrices. All members of this family of EOMs make use of alternative static gauge conditions than those used for standard ML-MCTDH. These alternative conditions result in an expansion of the wavefunction in terms of a set of potentially arbitrary orthonormal functions, rather than in terms of a set of non-orthonormal and potentially linearly dependent functions, as is the case for standard ML-MCTDH. We show that the EOMs used in the projector splitting integrator (PSI) and the invariant EOM approaches are two special cases of this family obtained from different choices for the dynamic gauge condition, with the invariant EOMs making use of a choice that introduces potentially unbounded operators into the EOMs. As a consequence, all arguments for the existence of parallelizable integration schemes for the invariant EOMs can also be applied to the PSI EOMs.
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Affiliation(s)
- Lachlan P Lindoy
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA
| | - Benedikt Kloss
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA
| | - David R Reichman
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA
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Weike T, Manthe U. The multi-configurational time-dependent Hartree approach in optimized second quantization: thermal ensembles and statistical sampling. Chem Phys 2021. [DOI: 10.1016/j.chemphys.2021.111413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Weike T, Manthe U. Symmetries in the multi-configurational time-dependent Hartree wavefunction representation and propagation. J Chem Phys 2021; 154:194108. [PMID: 34240912 DOI: 10.1063/5.0054105] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In multi-configurational time-dependent Hartree (MCTDH) approaches, different multi-layered wavefunction representations can be used to represent the same physical wavefunction. Transformations between different equivalent representations of a physical wavefunction that alter the tree structure used in the multi-layer MCTDH wavefunction representation interchange the role of single-particle functions (SPFs) and single-hole functions (SHFs) in the MCTDH formalism. While the physical wavefunction is invariant under these transformations, this invariance does not hold for the standard multi-layer MCTDH equations of motion. Introducing transformed SPFs, which obey normalization conditions typically associated with SHFs, revised equations of motion are derived. These equations do not show the singularities resulting from the inverse single-particle density matrix and are invariant under tree transformations. Based on the revised equations of motion, a new integration scheme is introduced. The scheme combines the advantages of the constant mean-field approach of Beck and Meyer [Z. Phys. D 42, 113 (1997)] and the singularity-free integrator suggested by Lubich [Appl. Math. Res. Express 2015, 311]. Numerical calculations studying the spin boson model in high dimensionality confirm the favorable properties of the new integration scheme.
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Affiliation(s)
- Thomas Weike
- Theoretische Chemie, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, D-33615 Bielefeld, Germany
| | - Uwe Manthe
- Theoretische Chemie, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, D-33615 Bielefeld, Germany
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Mainali S, Gatti F, Iouchtchenko D, Roy PN, Meyer HD. Comparison of the multi-layer multi-configuration time-dependent Hartree (ML-MCTDH) method and the density matrix renormalization group (DMRG) for ground state properties of linear rotor chains. J Chem Phys 2021; 154:174106. [PMID: 34241072 DOI: 10.1063/5.0047090] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We demonstrate the applicability of the Multi-Layer Multi-Configuration Time-Dependent Hartree (ML-MCTDH) method to the problem of computing ground states of one-dimensional chains of linear rotors with dipolar interactions. Specifically, we successfully obtain energies, entanglement entropies, and orientational correlations that are in agreement with the Density Matrix Renormalization Group (DMRG), which has been previously used for this system. We find that the entropies calculated by ML-MCTDH for larger system sizes contain nonmonotonicity, as expected in the vicinity of a second-order quantum phase transition between ordered and disordered rotor states. We observe that this effect remains when all couplings besides nearest-neighbor are omitted from the Hamiltonian, which suggests that it is not sensitive to the rate of decay of the interactions. In contrast to DMRG, which is tailored to the one-dimensional case, ML-MCTDH (as implemented in the Heidelberg MCTDH package) requires more computational time and memory, although the requirements are still within reach of commodity hardware. The numerical convergence and computational demand of two practical implementations of ML-MCTDH and DMRG are presented in detail for various combinations of system parameters.
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Affiliation(s)
- Samrit Mainali
- Université Paris-Saclay, Institut des Sciences Moléculaires d'Orsay ISMO, UMR CNRS 8214, F-91405 Orsay, France
| | - Fabien Gatti
- Université Paris-Saclay, Institut des Sciences Moléculaires d'Orsay ISMO, UMR CNRS 8214, F-91405 Orsay, France
| | - Dmitri Iouchtchenko
- 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
| | - Hans-Dieter Meyer
- Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany
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Tan JA, Kuo JL. Fermi resonance switching in KrH +Rg and XeH +Rg (Rg = Ne, Ar, Kr, and Xe). J Chem Phys 2021; 154:134302. [PMID: 33832263 DOI: 10.1063/5.0044703] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Matrix isolation experiments have been successfully employed to extensively study the infrared spectrum of several proton-bound rare gas complexes. Most of these studies have focused on the spectral signature for the H+ stretch (ν3) and its combination bands with the intermolecular stretch coordinate (ν1). However, little attention has been paid to the Fermi resonance interaction between the H+ stretch (ν3) and H+ bend overtone (2ν2) in the asymmetric proton-bound rare gas dimers, RgH+Rg'. In this work, we have investigated this interaction on KrH+Rg and XeH+Rg with Rg = (Ne, Ar, Kr, and Xe). A multilevel potential energy surface (PES) was used to simulate the vibrational structure of these complexes. This PES is a dual-level comprising of second-order Møller-Plesset perturbation theory and coupled-cluster singles doubles with perturbative triples [CCSD(T)] levels of ab initio theories. We found that when both the combination bands (nν1 + ν3) and bend overtone 2ν2 compete to borrow intensity from the ν3 band, the latter wins over the former, which then results in the suppression of the nν1 + ν3 bands. The current simulations offer new assignments for the ArH+Xe and KrH+Xe spectra. Complete basis set (CBS) binding energies for these complexes were also calculated at the CCSD(T)/CBS level.
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Affiliation(s)
- Jake A Tan
- Institute of Atomic and Molecular Sciences, Academia Sinica, No. 1 Roosevelt Road, Section 4, Da-an District, Taipei City 10617, Taiwan
| | - Jer-Lai Kuo
- Institute of Atomic and Molecular Sciences, Academia Sinica, No. 1 Roosevelt Road, Section 4, Da-an District, Taipei City 10617, Taiwan
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Zhao B, Manthe U. Direct product-type grid representations for angular coordinates in extended space and their application in the MCTDH approach. J Chem Phys 2021; 154:104115. [PMID: 33722051 DOI: 10.1063/5.0045054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Multi-configurational time-dependent Hartree (MCTDH) calculations using time-dependent grid representations can be used to accurately simulate high-dimensional quantum dynamics on general ab initio potential energy surfaces. Employing the correlation discrete variable representation, sets of direct product type grids are employed in the calculation of the required potential energy matrix elements. This direct product structure can be a problem if the coordinate system includes polar and azimuthal angles that result in singularities in the kinetic energy operator. In the present work, a new direct product-type discrete variable representation (DVR) for arbitrary sets of polar and azimuthal angles is introduced. It employs an extended coordinate space where the range of the polar angles is taken to be [-π, π]. The resulting extended space DVR resolves problems caused by the singularities in the kinetic energy operator without generating a very large spectral width. MCTDH calculations studying the F·CH4 complex are used to investigate important properties of the new scheme. The scheme is found to allow for more efficient integration of the equations of motion compared to the previously employed cot-DVR approach [G. Schiffel and U. Manthe, Chem. Phys. 374, 118 (2010)] and decreases the required central processing unit times by about an order of magnitude.
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Affiliation(s)
- Bin Zhao
- Theoretische Chemie, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, D-33615 Bielefeld, Germany
| | - Uwe Manthe
- Theoretische Chemie, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, D-33615 Bielefeld, Germany
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17
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Wang H, Meyer HD. Importance of Appropriately Regularizing the ML-MCTDH Equations of Motion. J Phys Chem A 2021; 125:3077-3087. [DOI: 10.1021/acs.jpca.0c11221] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Haobin Wang
- Department of Chemistry, University of Colorado Denver, Denver, Colorado 80217-3364, United States
| | - Hans-Dieter Meyer
- Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg, Germany
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18
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Bauer B, Bravyi S, Motta M, Chan GKL. Quantum Algorithms for Quantum Chemistry and Quantum Materials Science. Chem Rev 2020; 120:12685-12717. [DOI: 10.1021/acs.chemrev.9b00829] [Citation(s) in RCA: 134] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Bela Bauer
- Microsoft Quantum, Station Q, University of California
, Santa Barbara, California 93106, United States
| | - Sergey Bravyi
- IBM Quantum, IBM T. J. Watson Research Center
, Yorktown Heights, New York 10598, United States
| | - Mario Motta
- IBM Quantum, IBM Research Almaden
, San Jose, California 95120, United States
| | - Garnet Kin-Lic Chan
- Division of Chemistry and Chemical Engineering, California Institute of Technology
, Pasadena, California 91125, United States
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19
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Weike T, Manthe U. The multi-configurational time-dependent Hartree approach in optimized second quantization: Imaginary time propagation and particle number conservation. J Chem Phys 2020; 152:034101. [DOI: 10.1063/1.5140984] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Thomas Weike
- Theoretische Chemie, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, D-33615 Bielefeld, Germany
| | - Uwe Manthe
- Theoretische Chemie, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, D-33615 Bielefeld, Germany
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20
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Schröder M. Transforming high-dimensional potential energy surfaces into a canonical polyadic decomposition using Monte Carlo methods. J Chem Phys 2020; 152:024108. [DOI: 10.1063/1.5140085] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Markus Schröder
- Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg, Germany
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21
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Bertaina G, Di Liberto G, Ceotto M. Reduced rovibrational coupling Cartesian dynamics for semiclassical calculations: Application to the spectrum of the Zundel cation. J Chem Phys 2019; 151:114307. [PMID: 31542046 DOI: 10.1063/1.5114616] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We study the vibrational spectrum of the protonated water dimer, by means of a divide-and-conquer semiclassical initial value representation of the quantum propagator, as a first step in the study of larger protonated water clusters. We use the potential energy surface from the work of Huang et al. [J. Chem. Phys. 122, 044308 (2005)]. To tackle such an anharmonic and floppy molecule, we employ fully Cartesian dynamics and carefully reduce the coupling to global rotations in the definition of normal modes. We apply the time-averaging filter and obtain clean power spectra relative to suitable reference states that highlight the spectral peaks corresponding to the fundamental excitations of the system. Our trajectory-based approach allows for the physical interpretation of the very challenging proton transfer modes. We find that it is important, for such a floppy molecule, to selectively avoid initially exciting lower energy modes, in order to obtain cleaner spectra. The estimated vibrational energies display a mean absolute error (MAE) of ∼29 cm-1 with respect to available multiconfiguration time-dependent Hartree calculations and MAE ∼ 14 cm-1 when compared to the optically active experimental excitations of the Ne-tagged Zundel cation. The reasonable scaling in the number of trajectories for Monte Carlo convergence is promising for applications to higher dimensional protonated cluster systems.
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Affiliation(s)
- G Bertaina
- Dipartimento di Chimica, Università degli Studi di Milano, via C. Golgi 19, 20133 Milano, Italy
| | - G Di Liberto
- Dipartimento di Chimica, Università degli Studi di Milano, via C. Golgi 19, 20133 Milano, Italy
| | - M Ceotto
- Dipartimento di Chimica, Università degli Studi di Milano, via C. Golgi 19, 20133 Milano, Italy
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22
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Tan JA, Kuo JL. A theoretical study on the infrared signatures of proton-bound rare gas dimers (Rg-H +-Rg), Rg = {Ne, Ar, Kr, and Xe}. J Chem Phys 2019; 150:124305. [PMID: 30927880 DOI: 10.1063/1.5090031] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The infrared spectrum of proton-bound rare gas dimers has been extensively studied via matrix isolation spectroscopy. However, little attention has been paid on their spectrum in the gas phase. Most of the Rg2H+ has not been detected outside the matrix environment. Recently, ArnH+ (n = 3-7) has been first detected in the gas-phase [D. C. McDonald et al., J. Chem. Phys. 145, 231101 (2016)]. In that work, anharmonic theory can reproduce the observed vibrational structure. In this paper, we extend the existing theory to examine the vibrational signatures of Rg2H+, Rg = {Ne, Ar, Kr, and Xe}. The successive binding of Rg to H+ was investigated through the calculation of stepwise formation energies. It was found that this binding is anti-cooperative. High-level full-dimensional potential energy surfaces at the CCSD(T)/aug-cc-pVQZ//MP2/aug-cc-pVQZ were constructed and used in the anharmonic calculation via discrete variable representation. We found that the potential coupling between the symmetric and asymmetric Rg-H+ stretch (ν1 and ν3 respectively) causes a series of bright n1ν1 + ν3 progressions. From Ne2H+ to Xe2H+, an enhancement of intensities for these bands was observed.
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Affiliation(s)
- Jake A Tan
- Institute of Atomic and Molecular Sciences, Academia Sinica, No. 1 Roosevelt Road, Section 4, Taipei 10617, Taiwan
| | - Jer-Lai Kuo
- Institute of Atomic and Molecular Sciences, Academia Sinica, No. 1 Roosevelt Road, Section 4, Taipei 10617, Taiwan
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23
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Mandal S, Ghosh S, Sardar S, Adhikari S. The TDDVR approach for molecular photoexcitation, molecule–surface and triatomic reactive scattering processes. INT REV PHYS CHEM 2018. [DOI: 10.1080/0144235x.2018.1548103] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Souvik Mandal
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Jadavpur, India
| | - Sandip Ghosh
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Jadavpur, India
| | | | - Satrajit Adhikari
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Jadavpur, India
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24
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Tan JA, Kuo JL. Multilevel Approach for Direct VSCF/VCI MULTIMODE Calculations with Applications to Large “Zundel” Cations. J Chem Theory Comput 2018; 14:6405-6416. [DOI: 10.1021/acs.jctc.8b00679] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jake A. Tan
- Institute of Atomic and Molecular Sciences, Academia Sinica, No. 1 Roosevelt Road, Section 4, Taipei 10617, Taiwan (ROC)
| | - Jer-Lai Kuo
- Institute of Atomic and Molecular Sciences, Academia Sinica, No. 1 Roosevelt Road, Section 4, Taipei 10617, Taiwan (ROC)
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25
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Manthe U. Optimized unoccupied single-particle functions in the (multi-layer) multi-configurational time-dependent Hartree approach. Chem Phys 2018. [DOI: 10.1016/j.chemphys.2018.05.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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26
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Affiliation(s)
- Haobin Wang
- Department of Chemistry, University of Colorado Denver, Denver, Colorado 80217-3364, USA and Beijing Computational Science Research Center, No. 10 East Xibeiwang Road, Haidian District, Beijing 100193, China
| | - Hans-Dieter Meyer
- Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg, Germany
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27
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Di Liberto G, Conte R, Ceotto M. "Divide and conquer" semiclassical molecular dynamics: A practical method for spectroscopic calculations of high dimensional molecular systems. J Chem Phys 2018; 148:014307. [PMID: 29306274 DOI: 10.1063/1.5010388] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We extensively describe our recently established "divide-and-conquer" semiclassical method [M. Ceotto, G. Di Liberto, and R. Conte, Phys. Rev. Lett. 119, 010401 (2017)] and propose a new implementation of it to increase the accuracy of results. The technique permits us to perform spectroscopic calculations of high-dimensional systems by dividing the full-dimensional problem into a set of smaller dimensional ones. The partition procedure, originally based on a dynamical analysis of the Hessian matrix, is here more rigorously achieved through a hierarchical subspace-separation criterion based on Liouville's theorem. Comparisons of calculated vibrational frequencies to exact quantum ones for a set of molecules including benzene show that the new implementation performs better than the original one and that, on average, the loss in accuracy with respect to full-dimensional semiclassical calculations is reduced to only 10 wavenumbers. Furthermore, by investigating the challenging Zundel cation, we also demonstrate that the "divide-and-conquer" approach allows us to deal with complex strongly anharmonic molecular systems. Overall the method very much helps the assignment and physical interpretation of experimental IR spectra by providing accurate vibrational fundamentals and overtones decomposed into reduced dimensionality spectra.
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Affiliation(s)
- Giovanni Di Liberto
- Dipartimento di Chimica, Università degli Studi di Milano, Via C. Golgi 19, 20133 Milano, Italy
| | - Riccardo Conte
- Dipartimento di Chimica, Università degli Studi di Milano, Via C. Golgi 19, 20133 Milano, Italy
| | - Michele Ceotto
- Dipartimento di Chimica, Università degli Studi di Milano, Via C. Golgi 19, 20133 Milano, Italy
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28
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Otto F, Chiang YC, Peláez D. Accuracy of Potfit-based potential representations and its impact on the performance of (ML-)MCTDH. Chem Phys 2018. [DOI: 10.1016/j.chemphys.2017.11.013] [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]
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29
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Affiliation(s)
- Hans-Dieter Meyer
- Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg, Germany
| | - Haobin Wang
- Department of Chemistry, University of Colorado Denver, Denver, Colorado 80217-3364, USA and Beijing Computational Science Research Center, No. 10 East Xibeiwang Road, Haidian District, Beijing 100193, China
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30
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Yang J, Kong X, Jiang L. On the solvation of hydronium by carbon dioxide: Structural and infrared spectroscopic study of (H3O+)(CO2). Chem Phys 2018. [DOI: 10.1016/j.chemphys.2017.11.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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31
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Tsuge M, Tseng CY, Lee YP. Spectroscopy of prospective interstellar ions and radicals isolated in para-hydrogen matrices. Phys Chem Chem Phys 2018; 20:5344-5358. [DOI: 10.1039/c7cp05680j] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The p-H2 matrix-isolation technique coupled with photolysis in situ or electron bombardment produces protonated or hydrogenated species important in astrochemistry.
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Affiliation(s)
- Masashi Tsuge
- Department of Applied Chemistry and Institute of Molecular Science
- National Chiao Tung University
- Hsinchu 30010
- Taiwan
| | - Chih-Yu Tseng
- Department of Applied Chemistry and Institute of Molecular Science
- National Chiao Tung University
- Hsinchu 30010
- Taiwan
| | - Yuan-Pern Lee
- Department of Applied Chemistry and Institute of Molecular Science
- National Chiao Tung University
- Hsinchu 30010
- Taiwan
- Institute of Atomic and Molecular Sciences
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32
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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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33
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Pitsevich G, Malevich A, Kozlovskaya E, Shalamberidze E, Doroshenko I, Pogorelov V, Mahnach E, Sapeshko V, Balevicius V. MP4 study of the multimode coupling in protonated water dimer. J Mol Struct 2017. [DOI: 10.1016/j.molstruc.2017.03.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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34
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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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35
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Pitsevich G, Malevich A, Kozlovskaya E, Mahnach E, Doroshenko I, Pogorelov V, Pettersson LGM, Sablinskas V, Balevicius V. MP4 Study of the Anharmonic Coupling of the Shared Proton Stretching Vibration of the Protonated Water Dimer in Equilibrium and Transition States. J Phys Chem A 2017; 121:2151-2165. [PMID: 28187260 DOI: 10.1021/acs.jpca.7b00536] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The structure and harmonic and anharmonic IR spectra of the protonated water dimer (PWD) were calculated in C1, C2, and Cs symmetry at the MP4/acc-pVTZ level of theory. We found that structure and IR spectra are practically identical in C2 and C1 symmetry, demonstrating that an equilibrium C1 configuration of the PWD is not realized. Anharmonic coupling of the shared proton stretching vibration with all other modes in the PWD in C2 and Cs symmetry was the focus of this investigation. For this purpose, 28 two-dimensional potential energy surfaces (2D PES) were built at the MP4/acc-pVTZ level of theory and the corresponding vibrational Schrödinger equations were solved using the DVR method. Differences in the coupling of the investigated mode with other modes in the C2 and Cs configurations, along with some factors that determine the red- or blue-shift of the stretching vibration frequency, were analyzed. We obtained a rather reasonable value of the stretching frequency of the bridging proton (1058.4 cm-1) unperturbed by Fermi resonance. The Fermi resonance between the fundamental vibration ν7 and the combined vibration ν2 + ν6 of the same symmetry was analyzed through anharmonic second-order perturbation theory calculations, as well as by 3D PES constructed using Q2, Q6, and Q7 as normal coordinates. A significant (up to 50%) transfer of intensity from the fundamental vibration to the combined one was found. We have estimated the frequency of the bridging proton stretching vibration in the Cs configuration of the PWD based on calculations of the intrinsic anharmonicity and anharmonic double modes interactions at the MP4/acc-pVTZ level of theory (1261 cm-1).
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Affiliation(s)
- G Pitsevich
- Department of Physical Optics, Belarusian State University , Nezavisimosti ave., 4, 220030 Minsk, Belarus
| | - A Malevich
- Department of Physical Optics, Belarusian State University , Nezavisimosti ave., 4, 220030 Minsk, Belarus
| | - E Kozlovskaya
- Department of Physical Optics, Belarusian State University , Nezavisimosti ave., 4, 220030 Minsk, Belarus
| | - E Mahnach
- Department of Physical Optics, Belarusian State University , Nezavisimosti ave., 4, 220030 Minsk, Belarus
| | - I Doroshenko
- Taras Shevchenko National University of Kyiv , Volodymyrska str., 64\13, 01601, Kyiv, Ukraine
| | - V Pogorelov
- Taras Shevchenko National University of Kyiv , Volodymyrska str., 64\13, 01601, Kyiv, Ukraine
| | - Lars G M Pettersson
- Department of Physics, AlbaNova University Center, Stockholm University , S-106 91 Stockholm, Sweden
| | - V Sablinskas
- Faculty of Physics, Vilnius University , Sauletekio al. 9-3, LT-10222 Vilnius, Lithuania
| | - V Balevicius
- Faculty of Physics, Vilnius University , Sauletekio al. 9-3, LT-10222 Vilnius, Lithuania
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36
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Manthe U, Weike T. On the multi-layer multi-configurational time-dependent Hartree approach for bosons and fermions. J Chem Phys 2017; 146:064117. [DOI: 10.1063/1.4975662] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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37
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Talbot JJ, Cheng X, Herr JD, Steele RP. Vibrational Signatures of Electronic Properties in Oxidized Water: Unraveling the Anomalous Spectrum of the Water Dimer Cation. J Am Chem Soc 2016; 138:11936-45. [DOI: 10.1021/jacs.6b07182] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Justin J. Talbot
- Department
of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States
- Henry
Eyring Center for Theoretical Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States
| | - Xiaolu Cheng
- Department
of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States
- Henry
Eyring Center for Theoretical Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States
| | - Jonathan D. Herr
- Department
of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States
- Henry
Eyring Center for Theoretical Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States
| | - Ryan P. Steele
- Department
of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States
- Henry
Eyring Center for Theoretical Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States
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38
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Li Z, Vendrell O. Correlated proton-electron hole dynamics in protonated water clusters upon extreme ultraviolet photoionization. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2016; 3:043203. [PMID: 26798842 PMCID: PMC4714997 DOI: 10.1063/1.4939897] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 01/04/2016] [Indexed: 06/05/2023]
Abstract
The ultrafast nuclear and electronic dynamics of protonated water clusters H(+)(H2O) n after extreme ultraviolet photoionization is investigated. In particular, we focus on cluster cations with n = 3, 6, and 21. Upon ionization, two positive charges are present in the cluster related to the excess proton and the missing electron, respectively. A correlation is found between the cluster's geometrical conformation and initial electronic energy with the size of the final fragments produced. For situations in which the electron hole and proton are initially spatially close, the two entities become correlated and separate in a time-scale of 20 to 40 fs driven by strong non-adiabatic effects.
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39
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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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40
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Tan JA, Kuo JL. A closer examination of the coupling between ionic hydrogen bond (IHB) stretching and flanking group motions in (CH3OH)2H+: the strong isotope effects. Phys Chem Chem Phys 2016; 18:14531-42. [DOI: 10.1039/c6cp00309e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The intermode coupling between shared proton (O–H+–O) fundamental stretching and flanking modes in (CH3OH)2H+ was revisited in the following contexts: (1) evaluation of Hamiltonian matrix elements represented in a “pure state” (PS) basis and (2) tuning of coupling strengths using H/D isotopic substitution.
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Affiliation(s)
- Jake A. Tan
- Molecular Science and Technology Program
- Taiwan International Graduate Program
- Academia Sinica
- Taipei 115
- Republic Of China
| | - Jer-Lai Kuo
- Molecular Science and Technology Program
- Taiwan International Graduate Program
- Academia Sinica
- Taipei 115
- Republic Of China
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41
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Fagiani MR, Knorke H, Esser TK, Heine N, Wolke CT, Gewinner S, Schöllkopf W, Gaigeot MP, Spezia R, Johnson MA, Asmis KR. Gas phase vibrational spectroscopy of the protonated water pentamer: the role of isomers and nuclear quantum effects. Phys Chem Chem Phys 2016; 18:26743-26754. [DOI: 10.1039/c6cp05217g] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We use cryogenic ion trap vibrational spectroscopy to study the structure of the protonated water pentamer, H+(H2O)5, and its fully deuterated isotopologue, D+(D2O)5.
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Affiliation(s)
- Matias R. Fagiani
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie
- Universität Leipzig
- D-04103 Leipzig
- Germany
- Fritz-Haber-Institut der Max-Planck-Gesellschaft
| | - Harald Knorke
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie
- Universität Leipzig
- D-04103 Leipzig
- Germany
| | - Tim K. Esser
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie
- Universität Leipzig
- D-04103 Leipzig
- Germany
| | - Nadja Heine
- Fritz-Haber-Institut der Max-Planck-Gesellschaft
- D-14195 Berlin
- Germany
| | | | - Sandy Gewinner
- Fritz-Haber-Institut der Max-Planck-Gesellschaft
- D-14195 Berlin
- Germany
| | | | | | - Riccardo Spezia
- Université d’Evry Val d'Essonne
- UMR 8587 LAMBE
- 91025 Evry Cedex
- France
- CNRS
| | | | - Knut R. Asmis
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie
- Universität Leipzig
- D-04103 Leipzig
- Germany
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42
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Tan JA, Li JW, Chiu CC, Liao HY, Huynh HT, Kuo JL. Tuning the vibrational coupling of H3O+ by changing its solvation environment. Phys Chem Chem Phys 2016; 18:30721-30732. [DOI: 10.1039/c6cp06326h] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
This study demonstrates how the intermode coupling in the hydronium ion (H3O+) is modulated by the composition of the first solvation shell.
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Affiliation(s)
- Jake A. Tan
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Republic of China
- Department of Chemistry
| | - Jheng-Wei Li
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Republic of China
- Department of Physics
| | - Cheng-chau Chiu
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Republic of China
| | - Hsin-Yi Liao
- Department of Science Education
- National Taipei University of Education
- Taipei City 10671
- Republic of China
| | - Hai Thi Huynh
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Republic of China
| | - Jer-Lai Kuo
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Republic of China
- Molecular Science and Technology Program
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Tan JA, Kuo JL. Strong Quantum Coupling in the Vibrational Signatures of a Symmetric Ionic Hydrogen Bond: The Case of (CH3OH)2H+. J Phys Chem A 2015; 119:11320-8. [DOI: 10.1021/acs.jpca.5b10554] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jake A. Tan
- Molecular
Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, 128 Academia Road, Section 2, Nangang, Taipei 115, Taiwan, ROC
- Department
of Chemistry, National Tsing Hua University, 101 Kuang-Fu Road, Section 2, Hsinchu 30013, Taiwan, ROC
- Institute
of Atomic and Molecular Sciences, Academia Sinica, No.1 Roosevelt
Road, Section 4, Taipei 10617, Taiwan, ROC
| | - Jer-Lai Kuo
- Molecular
Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, 128 Academia Road, Section 2, Nangang, Taipei 115, Taiwan, ROC
- Institute
of Atomic and Molecular Sciences, Academia Sinica, No.1 Roosevelt
Road, Section 4, Taipei 10617, Taiwan, ROC
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44
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Manthe U. The multi-configurational time-dependent Hartree approach revisited. J Chem Phys 2015; 142:244109. [DOI: 10.1063/1.4922889] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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45
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Shimshovitz A, Bačić Z, Tannor DJ. The von Neumann basis in non-Cartesian coordinates: Application to floppy triatomic molecules. J Chem Phys 2014; 141:234106. [DOI: 10.1063/1.4902553] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
- Asaf Shimshovitz
- Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Zlatko Bačić
- Department of Chemistry, New York University, New York, New York 10003, USA
- NYU-ECNU Center of Computational Chemistry at NYU Shanghai, Shanghai 200062, China
| | - David J. Tannor
- Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel
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46
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Khan BA, Sardar S, Sarkar P, Adhikari S. Multisurface Multimode Molecular Dynamical Simulation of Naphthalene and Anthracene Radical Cations by Using Nearly Linear Scalable Time-Dependent Discrete Variable Representation Method. J Phys Chem A 2014; 118:11451-70. [PMID: 25426887 DOI: 10.1021/jp507459m] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Basir Ahamed Khan
- Department
of Physics, Krishnath College, Berhampore, West Bengal 742101, India
- Department
of Chemistry, Visva-Bharati University, Santiniketan, West Bengal 731235, India
| | - Subhankar Sardar
- Department
of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Pranab Sarkar
- Department
of Chemistry, Visva-Bharati University, Santiniketan, West Bengal 731235, India
| | - Satrajit Adhikari
- Department
of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
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47
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Li Z, El-Amine Madjet M, Vendrell O, Santra R. Core-level transient absorption spectroscopy as a probe of electron hole relaxation in photoionized H+(H2O)n. Faraday Discuss 2014; 171:457-70. [DOI: 10.1039/c4fd00078a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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48
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Roy TK, Carrington T, Gerber RB. Approximate first-principles anharmonic calculations of polyatomic spectra using MP2 and B3LYP potentials: comparisons with experiment. J Phys Chem A 2014; 118:6730-9. [PMID: 24977304 DOI: 10.1021/jp5060155] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Anharmonic vibrational spectroscopy calculations using MP2 and B3LYP computed potential surfaces are carried out for a series of molecules, and frequencies and intensities are compared with those from experiment. The vibrational self-consistent field with second-order perturbation correction (VSCF-PT2) is used in computing the spectra. The test calculations have been performed for the molecules HNO3, C2H4, C2H4O, H2SO4, CH3COOH, glycine, and alanine. Both MP2 and B3LYP give results in good accord with experimental frequencies, though, on the whole, MP2 gives very slightly better agreement. A statistical analysis of deviations in frequencies from experiment is carried out that gives interesting insights. The most probable percentage deviation from experimental frequencies is about -2% (to the red of the experiment) for B3LYP and +2% (to the blue of the experiment) for MP2. There is a higher probability for relatively large percentage deviations when B3LYP is used. The calculated intensities are also found to be in good accord with experiment, but the percentage deviations are much larger than those for frequencies. The results show that both MP2 and B3LYP potentials, used in VSCF-PT2 calculations, account well for anharmonic effects in the spectroscopy of molecules of the types considered.
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Affiliation(s)
- Tapta Kanchan Roy
- Institute of Chemistry and The Fritz Haber Research Center, The Hebrew University , Jerusalem 91904, Israel
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49
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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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50
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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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