1
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Iyengar SS, Schlegel HB, Sumner I, Li J. Rare Events Sampling Methods for Quantum and Classical Ab Initio Molecular Dynamics. J Phys Chem A 2024; 128:5386-5397. [PMID: 38951489 DOI: 10.1021/acs.jpca.3c07385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/03/2024]
Abstract
We provide an approach to sample rare events during classical ab initio molecular dynamics and quantum wavepacket dynamics. For classical AIMD, a set of fictitious degrees of freedom are introduced that may harmonically interact with the electronic and nuclear degrees of freedom to steer the dynamics in a conservative fashion toward energetically forbidden regions. A similar approach when introduced for quantum wavepacket dynamics has the effect of biasing the trajectory of the wavepacket centroid toward the regions of the potential surface that are difficult to sample. The approach is demonstrated for a phenol-amine system, which is a prototypical problem for condensed phase-proton transfer, and for model potentials undergoing wavepacket dynamics. In all cases, the approach yields trajectories that conserve energy while sampling rare events.
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Affiliation(s)
- Srinivasan S Iyengar
- Department of Chemistry, Department of Physics, and the Indiana University Quantum Science and Engineering Center (IU-QSEC), Indiana University, 800 E. Kirkwood Avenue, Bloomington 47405, Indiana, United States
| | - H Bernhard Schlegel
- Department of Chemistry, Wayne State University, Detroit 48202, Michigan, United States
| | - Isaiah Sumner
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg 22807, Virginia, United States
| | - Junjie Li
- Texas Advanced Computing Center, The University of Texas at Austin, Austin 78758, Texas, United States
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2
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Green AT, Martens CC. Zombie cats on the quantum-classical frontier: Wigner-Moyal and semiclassical limit dynamics of quantum coherence in molecules. J Chem Phys 2023; 159:204102. [PMID: 37991156 DOI: 10.1063/5.0177421] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 11/02/2023] [Indexed: 11/23/2023] Open
Abstract
In this paper, we investigate the time evolution of quantum coherence-the off-diagonal elements of the density matrix of a multistate quantum system-from the perspective of the Wigner-Moyal formalism. This approach provides an exact phase space representation of quantum mechanics. We consider the coherent evolution of nuclear wavepackets in a molecule with two electronic states. For harmonic potentials, the problem is analytically soluble for both a fully quantum mechanical description and a semiclassical description. We highlight the serious deficiencies of the semiclassical treatment of coherence for general systems and illustrate how even qualitative accuracy requires higher order terms in the Moyal expansion to be included. The model provides an experimentally relevant example of a molecular Schrödinger's cat state. The alive and dead cats of the exact two-state quantum evolution collapse into a "zombie" cat in the semiclassical limit-an averaged behavior, neither alive nor dead, leading to significant errors. The inclusion of the Moyal correction restores a faithful simultaneously alive and dead representation of the cat that is experimentally observable.
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Affiliation(s)
- Austin T Green
- University of California, Irvine, California 92697-2025, USA
| | - Craig C Martens
- University of California, Irvine, California 92697-2025, USA
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3
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Lassmann Y, Curchod BFE. Probing the sensitivity of ab initio multiple spawning to its parameters. Theor Chem Acc 2023; 142:66. [PMID: 37520272 PMCID: PMC10382418 DOI: 10.1007/s00214-023-03004-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 07/13/2023] [Indexed: 08/01/2023]
Abstract
Full multiple spawning (FMS) offers a strategy to simulate the nonadiabatic dynamics of molecular systems by describing their nuclear wavefunctions by a linear combination of coupled trajectory basis functions (TBFs). Applying a series of controlled approximations to the full multiple spawning (FMS) equations leads to the ab initio multiple spawning (AIMS), which is compatible with an on-the-fly propagation of the TBFs and an accurate description of nonadiabatic processes. The AIMS strategy and its numerical implementations, however, rely on a series of user-defined parameters. Herein, we investigate the influence of these parameters on the electronic-state population of two molecular systems- trans-azomethane and a two-dimensional model of the butatriene cation. This work highlights the stability of AIMS with respect to most of its parameters, underlines the specific parameters that require particular attention from the user of the method, and offers prescriptions for an informed selection of their value. Supplementary Information The online version contains supplementary material available at 10.1007/s00214-023-03004-w.
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Affiliation(s)
- Yorick Lassmann
- Centre for Computational Chemistry, School of Chemistry, Cantock’s Close, University of Bristol, Bristol, BS8 1TS UK
| | - Basile F. E. Curchod
- Centre for Computational Chemistry, School of Chemistry, Cantock’s Close, University of Bristol, Bristol, BS8 1TS UK
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4
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Gelin MF, Chen L, Domcke W. Equation-of-Motion Methods for the Calculation of Femtosecond Time-Resolved 4-Wave-Mixing and N-Wave-Mixing Signals. Chem Rev 2022; 122:17339-17396. [PMID: 36278801 DOI: 10.1021/acs.chemrev.2c00329] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Femtosecond nonlinear spectroscopy is the main tool for the time-resolved detection of photophysical and photochemical processes. Since most systems of chemical interest are rather complex, theoretical support is indispensable for the extraction of the intrinsic system dynamics from the detected spectroscopic responses. There exist two alternative theoretical formalisms for the calculation of spectroscopic signals, the nonlinear response-function (NRF) approach and the spectroscopic equation-of-motion (EOM) approach. In the NRF formalism, the system-field interaction is assumed to be sufficiently weak and is treated in lowest-order perturbation theory for each laser pulse interacting with the sample. The conceptual alternative to the NRF method is the extraction of the spectroscopic signals from the solutions of quantum mechanical, semiclassical, or quasiclassical EOMs which govern the time evolution of the material system interacting with the radiation field of the laser pulses. The NRF formalism and its applications to a broad range of material systems and spectroscopic signals have been comprehensively reviewed in the literature. This article provides a detailed review of the suite of EOM methods, including applications to 4-wave-mixing and N-wave-mixing signals detected with weak or strong fields. Under certain circumstances, the spectroscopic EOM methods may be more efficient than the NRF method for the computation of various nonlinear spectroscopic signals.
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Affiliation(s)
- Maxim F Gelin
- School of Science, Hangzhou Dianzi University, Hangzhou 310018, China
| | - Lipeng Chen
- Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Strasse 38, D-01187 Dresden, Germany
| | - Wolfgang Domcke
- Department of Chemistry, Technical University of Munich, D-85747 Garching,Germany
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5
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Joubert-Doriol L. Variational Approach for Linearly Dependent Moving Bases in Quantum Dynamics: Application to Gaussian Functions. J Chem Theory Comput 2022; 18:5799-5809. [PMID: 36166838 DOI: 10.1021/acs.jctc.2c00461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this paper, we present a variational treatment of the linear dependence for a non-orthogonal time-dependent basis set in solving the Schrödinger equation. The method is based on (i) the definition of a linearly independent working space and (ii) a variational construction of the propagator over finite time steps. The second point allows the method to properly account for changes in the dimensionality of the working space along the time evolution. In particular, the time evolution is represented by a semi-unitary transformation. Tests are carried out on a quartic double-well potential with Gaussian basis functions whose centers evolve according to classical equations of motion. We show that the resulting dynamics converges to the exact one and is unitary by construction.
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Affiliation(s)
- Loïc Joubert-Doriol
- Université Gustave Eiffel, Université Paris-Est Créteil, CNRS, UMR 8208, MSME, F-77454 Marne-la-Vallée, France
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6
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Floquet Hamiltonian for incorporating electronic excitation by a laser pulse into simulations of non-adiabatic dynamics. Chem Phys 2018. [DOI: 10.1016/j.chemphys.2018.07.048] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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7
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Affiliation(s)
- Basile F. E. Curchod
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - Todd J. Martínez
- Department of Chemistry and PULSE Institute, Stanford University, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
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8
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Li Z, Inhester L, Liekhus-Schmaltz C, Curchod BFE, Snyder JW, Medvedev N, Cryan J, Osipov T, Pabst S, Vendrell O, Bucksbaum P, Martinez TJ. Ultrafast isomerization in acetylene dication after carbon K-shell ionization. Nat Commun 2017; 8:453. [PMID: 28878226 PMCID: PMC5587545 DOI: 10.1038/s41467-017-00426-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Accepted: 06/28/2017] [Indexed: 11/09/2022] Open
Abstract
Ultrafast proton migration and isomerization are key processes for acetylene and its ions. However, the mechanism for ultrafast isomerization of acetylene [HCCH]2+ to vinylidene [H2CC]2+ dication remains nebulous. Theoretical studies show a large potential barrier ( > 2 eV) for isomerization on low-lying dicationic states, implying picosecond or longer isomerization timescales. However, a recent experiment at a femtosecond X-ray free-electron laser suggests sub-100 fs isomerization. Here we address this contradiction with a complete theoretical study of the dynamics of acetylene dication produced by Auger decay after X-ray photoionization of the carbon atom K shell. We find no sub-100 fs isomerization, while reproducing the salient features of the time-resolved Coulomb imaging experiment. This work resolves the seeming contradiction between experiment and theory and also calls for careful interpretation of structural information from the widely applied Coulomb momentum imaging method. The timescale of isomerization in molecules involving ultrafast migration of constituent atoms is difficult to measure. Here the authors report that sub-100 fs isomerization time on acetylene dication in lower electronic states is not possible and point to misinterpretation of recent experimental results.
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Affiliation(s)
- Zheng Li
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California, 94025, USA.,Department of Chemistry and the PULSE Institute, Stanford University, 333 Campus Drive, Stanford, California, 94305, USA
| | - Ludger Inhester
- Center for Free Electron Laser Science, Deutsches Elektronen-Synchrotron, Notkestraße 85, D-22607, Hamburg, Germany.,Hamburg Center for Ultrafast Imaging, Luruper Chaussee 149, D-22761, Hamburg, Germany
| | - Chelsea Liekhus-Schmaltz
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California, 94025, USA.,Department of Physics, Stanford University, 382 Via Pueblo Mall, Stanford, California, 94305, USA
| | - Basile F E Curchod
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California, 94025, USA.,Department of Chemistry and the PULSE Institute, Stanford University, 333 Campus Drive, Stanford, California, 94305, USA
| | - James W Snyder
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California, 94025, USA.,Department of Chemistry and the PULSE Institute, Stanford University, 333 Campus Drive, Stanford, California, 94305, USA
| | - Nikita Medvedev
- Center for Free Electron Laser Science, Deutsches Elektronen-Synchrotron, Notkestraße 85, D-22607, Hamburg, Germany.,Department of Radiation and Chemical Physics, Institute of Physics, Czech Academy of Sciences, Na Slovance 2, 182 21, Prague 8, Czech Republic.,Laser Plasma Department, Institute of Plasma Physics, Czech Academy of Sciences, Za Slovankou 3, 182 00, Prague 8, Czech Republic
| | - James Cryan
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California, 94025, USA
| | - Timur Osipov
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California, 94025, USA
| | - Stefan Pabst
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts, 02138, USA
| | - Oriol Vendrell
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000, Aarhus, Denmark
| | - Phil Bucksbaum
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California, 94025, USA.,Department of Physics, Stanford University, 382 Via Pueblo Mall, Stanford, California, 94305, USA
| | - Todd J Martinez
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California, 94025, USA. .,Department of Chemistry and the PULSE Institute, Stanford University, 333 Campus Drive, Stanford, California, 94305, USA.
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9
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A b initio quantum direct dynamics simulations of ultrafast photochemistry with Multiconfigurational Ehrenfest approach. Chem Phys 2017. [DOI: 10.1016/j.chemphys.2017.04.003] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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10
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Mignolet B, Curchod BFE, Martínez TJ. Communication: XFAIMS-eXternal Field Ab Initio Multiple Spawning for electron-nuclear dynamics triggered by short laser pulses. J Chem Phys 2017; 145:191104. [PMID: 27875877 DOI: 10.1063/1.4967761] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Attoscience is an emerging field where attosecond pulses or few cycle IR pulses are used to pump and probe the correlated electron-nuclear motion of molecules. We present the trajectory-guided eXternal Field Ab Initio Multiple Spawning (XFAIMS) method that models such experiments "on-the-fly," from laser pulse excitation to fragmentation or nonadiabatic relaxation to the ground electronic state. For the photoexcitation of the LiH molecule, we show that XFAIMS gives results in close agreement with numerically exact quantum dynamics simulations, both for atto- and femtosecond laser pulses. We then show the ability of XFAIMS to model the dynamics in polyatomic molecules by studying the effect of nuclear motion on the photoexcitation of a sulfine (H2CSO).
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Affiliation(s)
- Benoit Mignolet
- Department of Chemistry, University of Liège, 4000 Liège, Belgium
| | - Basile F E Curchod
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol, United Kingdom
| | - Todd J Martínez
- Department of Chemistry and the PULSE Institute, Stanford University, Stanford, California 94305, USA
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11
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Abstract
We present a generalized non-Hermitian equation of motion (nH-EOM) to go beyond standard trajectory surface hopping dynamics. The derivation is based on the Born-Huang expansion of the total wave function and the polar representation of the nuclear factor. The nH-EOM contains two additional terms, a skew symmetry term iΓ with dissipation operator Γ to account for decoherence, and a kinetic-energy renormalization term to account for phase shifts, without destroying the invariance to the choice of representation. Numerically, the nH-EOM can still be solved efficiently using a semiclassical approximation in the framework of Tully's fewest-switches surface hopping (FSSH) algorithm. Applications to model Hamiltonians demonstrate improved performance over the standard FSSH approach, through comparison to exact quantum results.
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Affiliation(s)
- Xing Gao
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz, D-45470, Mülheim an der Ruhr, Germany
| | - Walter Thiel
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz, D-45470, Mülheim an der Ruhr, Germany
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12
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Heaps CW, Mazziotti DA. Accurate non-adiabatic quantum dynamics from pseudospectral sampling of time-dependent Gaussian basis sets. J Chem Phys 2016. [DOI: 10.1063/1.4959872] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Charles W. Heaps
- Department of Chemistry and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA
| | - David A. Mazziotti
- Department of Chemistry and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA
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13
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Snyder JW, Curchod BFE, Martínez TJ. GPU-Accelerated State-Averaged Complete Active Space Self-Consistent Field Interfaced with Ab Initio Multiple Spawning Unravels the Photodynamics of Provitamin D3. J Phys Chem Lett 2016; 7:2444-2449. [PMID: 27266759 DOI: 10.1021/acs.jpclett.6b00970] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Excited-state molecular dynamics is essential to the study of photochemical reactions, which occur under nonequilibrium conditions. However, the computational cost of such simulations has often dictated compromises between accuracy and efficiency. The need for an accurate description of both the molecular electronic structure and nuclear dynamics has historically stymied the simulation of medium- to large-size molecular systems. Here, we show how to alleviate this problem by combining ab initio multiple spawning (AIMS) for the nuclear dynamics and GPU-accelerated state-averaged complete active space self-consistent field (SA-CASSCF) for the electronic structure. We demonstrate the new approach by first-principles SA-CASSCF/AIMS nonadiabatic dynamics simulation of photoinduced electrocyclic ring-opening in the 51-atom provitamin D3 molecule.
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Affiliation(s)
- James W Snyder
- Department of Chemistry and The PULSE Institute, Stanford University , Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Basile F E Curchod
- Department of Chemistry and The PULSE Institute, Stanford University , Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Todd J Martínez
- Department of Chemistry and The PULSE Institute, Stanford University , Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
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14
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Heaps CW, Mazziotti DA. Pseudospectral Gaussian quantum dynamics: Efficient sampling of potential energy surfaces. J Chem Phys 2016; 144:164108. [DOI: 10.1063/1.4946807] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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15
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Green JA, Grigolo A, Ronto M, Shalashilin DV. A two-layer approach to the coupled coherent states method. J Chem Phys 2016; 144:024111. [DOI: 10.1063/1.4939205] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- James A. Green
- School of Chemistry, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Adriano Grigolo
- Instituto de Física “Gleb Wataghin,” Universidade Estadual de Campinas, 13083-859 Campinas, SP, Brazil
| | - Miklos Ronto
- School of Chemistry, University of Leeds, Leeds LS2 9JT, United Kingdom
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16
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Liu L, Liu J, Martinez TJ. Dynamical Correlation Effects on Photoisomerization: Ab Initio Multiple Spawning Dynamics with MS-CASPT2 for a Model trans-Protonated Schiff Base. J Phys Chem B 2016; 120:1940-9. [DOI: 10.1021/acs.jpcb.5b09838] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Lihong Liu
- Key
Laboratory of Theoretical and Computational Photochemistry, Ministry
of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
- Department
of Chemistry and PULSE Institute, Stanford University, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94309, United States
| | - Jian Liu
- Department
of Chemistry and PULSE Institute, Stanford University, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94309, United States
- Beijing
National Laboratory for Molecular Sciences, Institute of Theoretical
and Computational Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Todd J. Martinez
- Department
of Chemistry and PULSE Institute, Stanford University, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94309, United States
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17
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Makhov DV, Martinez TJ, Shalashilin DV. Toward fully quantum modelling of ultrafast photodissociation imaging experiments. Treating tunnelling in the ab initio multiple cloning approach. Faraday Discuss 2016; 194:81-94. [DOI: 10.1039/c6fd00073h] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present an account of our recent effort to improve simulation of the photodissociation of small heteroaromatic molecules using the Ab Initio Multiple Cloning (AIMC) algorithm. The ultimate goal is to create a quantitative and converged technique for fully quantum simulations which treats both electrons and nuclei on a fully quantum level. We calculate and analyse the total kinetic energy release (TKER) spectra and Velocity Map Images (VMI), and compare the results directly with experimental measurements. In this work, we perform new extensive calculations using an improved AIMC algorithm that now takes into account the tunnelling of hydrogen atoms. This can play an extremely important role in photodissociation dynamics.
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18
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Fernandez-Alberti S, Makhov DV, Tretiak S, Shalashilin DV. Non-adiabatic excited state molecular dynamics of phenylene ethynylene dendrimer using a multiconfigurational Ehrenfest approach. Phys Chem Chem Phys 2016; 18:10028-40. [DOI: 10.1039/c5cp07332d] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Photoinduced dynamics of electronic and vibrational unidirectional energy transfer between meta-linked building blocks in a phenylene ethynylene dendrimer is simulated using a multiconfigurational Ehrenfest in time-dependent diabatic basis (MCE-TDDB) method.
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Affiliation(s)
| | | | - Sergei Tretiak
- Center for Nonlinear Studies (CNLS)
- and Center for Integrated Nanotechnologies (CINT)
- Los Alamos National Laboratory
- Los Alamos
- USA
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19
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Saller MAC, Habershon S. Basis Set Generation for Quantum Dynamics Simulations Using Simple Trajectory-Based Methods. J Chem Theory Comput 2014; 11:8-16. [DOI: 10.1021/ct500657f] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Maximilian A. C. Saller
- Department
of Chemistry and
Centre for Scientific Computing, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - Scott Habershon
- Department
of Chemistry and
Centre for Scientific Computing, University of Warwick, Coventry, CV4 7AL, United Kingdom
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20
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Makhov DV, Glover WJ, Martinez TJ, Shalashilin DV. Ab initio multiple cloning algorithm for quantum nonadiabatic molecular dynamics. J Chem Phys 2014; 141:054110. [DOI: 10.1063/1.4891530] [Citation(s) in RCA: 139] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Dmitry V. Makhov
- Department of Chemistry, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - William J. Glover
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, USA and SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Todd J. Martinez
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, USA and SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
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21
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Šulc M, Hernández H, Martínez TJ, Vaníček J. Relation of exact Gaussian basis methods to the dephasing representation: theory and application to time-resolved electronic spectra. J Chem Phys 2014; 139:034112. [PMID: 23883015 DOI: 10.1063/1.4813124] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We recently showed that the dephasing representation (DR) provides an efficient tool for computing ultrafast electronic spectra and that further acceleration is possible with cellularization [M. Šulc and J. Vaníček, Mol. Phys. 110, 945 (2012)]. Here, we focus on increasing the accuracy of this approximation by first implementing an exact Gaussian basis method, which benefits from the accuracy of quantum dynamics and efficiency of classical dynamics. Starting from this exact method, the DR is derived together with ten other methods for computing time-resolved spectra with intermediate accuracy and efficiency. These methods include the Gaussian DR, an exact generalization of the DR, in which trajectories are replaced by communicating frozen Gaussian basis functions evolving classically with an average Hamiltonian. The newly obtained methods are tested numerically on time correlation functions and time-resolved stimulated emission spectra in the harmonic potential, pyrazine S0∕S1 model, and quartic oscillator. Numerical results confirm that both the Gaussian basis method and the Gaussian DR increase the accuracy of the DR. Surprisingly, in chaotic systems the Gaussian DR can outperform the presumably more accurate Gaussian basis method, in which the two bases are evolved separately.
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Affiliation(s)
- Miroslav Šulc
- Laboratory of Theoretical Physical Chemistry, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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22
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Schwerdtfeger CA, Soudackov AV, Hammes-Schiffer S. Nonadiabatic dynamics of electron transfer in solution: Explicit and implicit solvent treatments that include multiple relaxation time scales. J Chem Phys 2014; 140:034113. [DOI: 10.1063/1.4855295] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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23
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Akimov AV, Prezhdo OV. The PYXAID Program for Non-Adiabatic Molecular Dynamics in Condensed Matter Systems. J Chem Theory Comput 2013; 9:4959-72. [DOI: 10.1021/ct400641n] [Citation(s) in RCA: 425] [Impact Index Per Article: 38.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Alexey V. Akimov
- Department
of Chemistry, University of Rochester, Rochester, New York 14627, United States
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Oleg V. Prezhdo
- Department
of Chemistry, University of Rochester, Rochester, New York 14627, United States
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24
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Akimov AV, Neukirch AJ, Prezhdo OV. Theoretical Insights into Photoinduced Charge Transfer and Catalysis at Oxide Interfaces. Chem Rev 2013; 113:4496-565. [DOI: 10.1021/cr3004899] [Citation(s) in RCA: 402] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Alexey V. Akimov
- Department of Chemistry, University of Rochester, Rochester, New York 14627,
United States
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973-5000,
United States
| | - Amanda J. Neukirch
- Department
of Physics and Astronomy, University of Rochester, Rochester, New York 14627,
United States
| | - Oleg V. Prezhdo
- Department of Chemistry, University of Rochester, Rochester, New York 14627,
United States
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Meier K, Choutko A, Dolenc J, Eichenberger AP, Riniker S, van Gunsteren WF. Multi-Resolution Simulation of Biomolecular Systems: A Review of Methodological Issues. Angew Chem Int Ed Engl 2013; 52:2820-34. [DOI: 10.1002/anie.201205408] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 09/12/2012] [Indexed: 01/01/2023]
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Meier K, Choutko A, Dolenc J, Eichenberger AP, Riniker S, van Gunsteren WF. Biomolekulare Simulationen mit mehreren Auflösungsniveaus: ein Überblick über methodische Aspekte. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201205408] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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27
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Pacheco AB, Dietrick SM, Stevens PS, Iyengar SS. "Pump-probe" atom-centered density matrix propagation studies to gauge anharmonicity and energy repartitioning in atmospheric reactive adducts: case study of the OH + isoprene and OH + butadiene reaction intermediates. J Phys Chem A 2012; 116:4108-28. [PMID: 22401490 DOI: 10.1021/jp212330e] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Time-resolved "pump-probe" ab initio molecular dynamics studies are constructed to probe the stability of reaction intermediates, the mechanism of energy transfer, and energy repartitioning, for moieties involved during the interaction of volatile organic compunds with hydroxyl radical. These systems are of prime importance in the atmosphere. Specifically, the stability of reaction intermediates of hydroxyl radical adducts to isoprene and butadiene molecules is used as a case study to develop novel computational techniques involving "pump-probe" ab initio molecular dynamics. Starting with the various possible hydroxyl radical adducts to isoprene and butadiene, select vibrational modes of each of the adducts are populated with excess energy to mimic the initial conditions of an experiment. The flow of energy into the remaining modes is then probed by subjecting the excited adducts to ab initio molecular dynamics simulations. It is found that the stability of the adducts arises directly due to the anhormonically driven coupling of the modes to facilitate repartitioning of the excess vibrational energy. This kind of vibrational repartitioning has a critical influence on the energy density.
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Affiliation(s)
- Alexander B Pacheco
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA
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DOLTSINIS NIKOSL, MARX DOMINIK. FIRST PRINCIPLES MOLECULAR DYNAMICS INVOLVING EXCITED STATES AND NONADIABATIC TRANSITIONS. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2012. [DOI: 10.1142/s0219633602000257] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Extensions of traditional molecular dynamics to excited electronic states and non-Born–Oppenheimer dynamics are reviewed focusing on applicability to chemical reactions of large molecules, possibly in condensed phases. The latter imposes restrictions on both the level of accuracy of the underlying electronic structure theory and the treatment of nonadiabaticity. This review, therefore, exclusively deals with ab initio "on the fly" molecular dynamics methods. For the same reason, mainly mixed quantum-classical approaches to nonadiabatic dynamics are considered.
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Affiliation(s)
- NIKOS L. DOLTSINIS
- Lehrstuhl für Theoretische Chemie, Ruhr–Universität Bochum, 44780 Bochum, Germany
| | - DOMINIK MARX
- Lehrstuhl für Theoretische Chemie, Ruhr–Universität Bochum, 44780 Bochum, Germany
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29
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Habershon S. Linear dependence and energy conservation in Gaussian wavepacket basis sets. J Chem Phys 2012; 136:014109. [DOI: 10.1063/1.3671978] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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30
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Dietrick SM, Pacheco AB, Phatak P, Stevens PS, Iyengar SS. Influence of Water on Anharmonicity, Stability, and Vibrational Energy Distribution of Hydrogen-Bonded Adducts in Atmospheric Reactions: Case Study of the OH + Isoprene Reaction Intermediate Using Ab Initio Molecular Dynamics. J Phys Chem A 2011; 116:399-414. [DOI: 10.1021/jp204511v] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Scott M. Dietrick
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Alexander B. Pacheco
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Prasad Phatak
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Philip S. Stevens
- Department of Chemistry and Center for Research in Environmental Science, School of Public and Environmental Affairs, Indiana University, Bloomington, Indiana 47405, United States
| | - Srinivasan S. Iyengar
- Departments of Chemistry and Physics, Indiana University, Bloomington, Indiana 47405, United States
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31
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Hocker D, Li X, Iyengar SS. Shannon Entropy Based Time-Dependent Deterministic Sampling for Efficient “On-the-Fly” Quantum Dynamics and Electronic Structure. J Chem Theory Comput 2011; 7:256-68. [DOI: 10.1021/ct1005856] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- David Hocker
- Department of Chemistry and Department of Physics, Indiana University, 800 E. Kirkwood Ave, Bloomington, Indiana 47405, United States
| | - Xiaohu Li
- Department of Chemistry and Department of Physics, Indiana University, 800 E. Kirkwood Ave, Bloomington, Indiana 47405, United States
| | - Srinivasan S. Iyengar
- Department of Chemistry and Department of Physics, Indiana University, 800 E. Kirkwood Ave, Bloomington, Indiana 47405, United States
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32
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Levine BG, Martínez TJ. Ab Initio Multiple Spawning Dynamics of Excited Butadiene: Role of Charge Transfer. J Phys Chem A 2009; 113:12815-24. [DOI: 10.1021/jp907111u] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Benjamin G. Levine
- Department of Chemistry and The Beckman Institute, University of Illinois, Urbana, Illinois 61801
| | - Todd J. Martínez
- Department of Chemistry and The Beckman Institute, University of Illinois, Urbana, Illinois 61801
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33
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Yang S, Coe JD, Kaduk B, Martínez TJ. An “optimal” spawning algorithm for adaptive basis set expansion in nonadiabatic dynamics. J Chem Phys 2009; 130:134113. [DOI: 10.1063/1.3103930] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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34
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Kina D, Nakayama A, Noro T, Taketsugu T, Gordon MS. Ab Initio QM/MM Molecular Dynamics Study on the Excited-State Hydrogen Transfer of 7-Azaindole in Water Solution. J Phys Chem A 2008; 112:9675-83. [DOI: 10.1021/jp804368p] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Daisuke Kina
- Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Akira Nakayama
- Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Takeshi Noro
- Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Tetsuya Taketsugu
- Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Mark S. Gordon
- Department of Chemistry, Iowa State University, Ames, Iowa 50011
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36
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Coe JD, J. Martinez T. Ab initio multiple spawning dynamics of excited state intramolecular proton transfer: the role of spectroscopically dark states. Mol Phys 2008. [DOI: 10.1080/00268970801901514] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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37
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The Study of Dynamically Averaged Vibrational Spectroscopy of Atmospherically Relevant Clusters Using Ab Initio Molecular Dynamics in Conjunction with Quantum Wavepackets. ADVANCES IN QUANTUM CHEMISTRY 2008. [DOI: 10.1016/s0065-3276(07)00216-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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38
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Ben-Nun M, Martínez TJ. A Continuous Spawning Method for Nonadiabatic Dynamics and Validation for the Zero-Temperature Spin-Boson Problem. Isr J Chem 2007. [DOI: 10.1560/ijc.47.1.75] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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39
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Sumner I, Iyengar SS. Quantum Wavepacket Ab Initio Molecular Dynamics: An Approach for Computing Dynamically Averaged Vibrational Spectra Including Critical Nuclear Quantum Effects. J Phys Chem A 2007; 111:10313-24. [PMID: 17894476 DOI: 10.1021/jp074522d] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
We have introduced a computational methodology to study vibrational spectroscopy in clusters inclusive of critical nuclear quantum effects. This approach is based on the recently developed quantum wavepacket ab initio molecular dynamics method that combines quantum wavepacket dynamics with ab initio molecular dynamics. The computational efficiency of the dynamical procedure is drastically improved (by several orders of magnitude) through the utilization of wavelet-based techniques combined with the previously introduced time-dependent deterministic sampling procedure measure to achieve stable, picosecond length, quantum-classical dynamics of electrons and nuclei in clusters. The dynamical information is employed to construct a novel cumulative flux/velocity correlation function, where the wavepacket flux from the quantized particle is combined with classical nuclear velocities to obtain the vibrational density of states. The approach is demonstrated by computing the vibrational density of states of [Cl-H-Cl]-, inclusive of critical quantum nuclear effects, and our results are in good agreement with experiment. A general hierarchical procedure is also provided, based on electronic structure harmonic frequencies, classical ab initio molecular dynamics, computation of nuclear quantum-mechanical eigenstates, and employing quantum wavepacket ab initio dynamics to understand vibrational spectroscopy in hydrogen-bonded clusters that display large degrees of anharmonicities.
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Affiliation(s)
- Isaiah Sumner
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, USA
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40
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Domcke W, Stock G. Theory of Ultrafast Nonadiabatic Excited-State Processes and their Spectroscopic Detection in Real Time. ADVANCES IN CHEMICAL PHYSICS 2007. [DOI: 10.1002/9780470141595.ch1] [Citation(s) in RCA: 250] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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41
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Robb MA, Garavelli M, Olivucci M, Bernardi F. A Computational Strategy for Organic Photochemistry. REVIEWS IN COMPUTATIONAL CHEMISTRY 2007. [DOI: 10.1002/9780470125922.ch2] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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42
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Jakowski J, Sumner I, Iyengar SS. Computational Improvements to Quantum Wave Packet ab Initio Molecular Dynamics Using a Potential-Adapted, Time-Dependent Deterministic Sampling Technique. J Chem Theory Comput 2006; 2:1203-19. [DOI: 10.1021/ct600131g] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Jacek Jakowski
- Departments of Chemistry and Physics, Indiana University, 800 E. Kirkwood Avenue, Bloomington, Indiana 47405
| | - Isaiah Sumner
- Departments of Chemistry and Physics, Indiana University, 800 E. Kirkwood Avenue, Bloomington, Indiana 47405
| | - Srinivasan S. Iyengar
- Departments of Chemistry and Physics, Indiana University, 800 E. Kirkwood Avenue, Bloomington, Indiana 47405
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43
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Iyengar SS, Jakowski J. Quantum wave packet ab initio molecular dynamics: an approach to study quantum dynamics in large systems. J Chem Phys 2006; 122:114105. [PMID: 15836199 DOI: 10.1063/1.1871876] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
A methodology to efficiently conduct simultaneous dynamics of electrons and nuclei is presented. The approach involves quantum wave packet dynamics using an accurate banded, sparse and Toeplitz representation for the discrete free propagator, in conjunction with ab initio molecular dynamics treatment of the electronic and classical nuclear degree of freedom. The latter may be achieved either by using atom-centered density-matrix propagation or by using Born-Oppenheimer dynamics. The two components of the methodology, namely, quantum dynamics and ab initio molecular dynamics, are harnessed together using a time-dependent self-consistent field-like coupling procedure. The quantum wave packet dynamics is made computationally robust by using adaptive grids to achieve optimized sampling. One notable feature of the approach is that important quantum dynamical effects including zero-point effects, tunneling, as well as over-barrier reflections are treated accurately. The electronic degrees of freedom are simultaneously handled at accurate levels of density functional theory, including hybrid or gradient corrected approximations. Benchmark calculations are provided for proton transfer systems and the dynamics results are compared with exact calculations to determine the accuracy of the approach.
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Affiliation(s)
- Srinivasan S Iyengar
- Department of Chemistry and Department of Physics, Indiana University, Bloomington, 47405, USA.
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44
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Riga JM, Fredj E, Martens CC. Simulation of vibrational dephasing of I2 in solid Kr using the semiclassical Liouville method. J Chem Phys 2006; 124:64506. [PMID: 16483219 DOI: 10.1063/1.2162878] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this paper, we present simulations of the decay of quantum coherence between vibrational states of I(2) in its ground (X) electronic state embedded in a cryogenic Kr matrix. We employ a numerical method based on the semiclassical limit of the quantum Liouville equation, which allows the simulation of the evolution and decay of quantum vibrational coherence using classical trajectories and ensemble averaging. The vibrational level-dependent interaction of the I(2)(X) oscillator with the rare-gas environment is modeled using a recently developed method for constructing state-dependent many-body potentials for quantum vibrations in a many-body classical environment [J. M. Riga, E. Fredj, and C. C. Martens, J. Chem. Phys. 122, 174107 (2005)]. The vibrational dephasing rates gamma(0n) for coherences prepared between the ground vibrational state mid R:0 and excited vibrational state mid R:n are calculated as a function of n and lattice temperature T. Excellent agreement with recent experiments performed by Karavitis et al. [Phys. Chem. Chem. Phys. 7, 791 (2005)] is obtained.
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Affiliation(s)
- Jeanne M Riga
- Department of Chemistry, University of California, Irvine, 92697-2025, USA
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45
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Gindensperger E, Meier C, Beswick JA, Parlant G. Combining fixed- and moving-grid methods to study direct dissociation processes involving nonadiabatic transitions. J Chem Phys 2005; 123:214107. [PMID: 16356039 DOI: 10.1063/1.2114807] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
We present a novel quantum-dynamics approach suitable for computing direct dissociation processes, including electronic transitions. This approach combines quantum trajectories in the Lagrangian reference frame with standard fixed-grid wave packets in order to overcome the limitations and difficulties of both techniques. As a model application, we consider the ultrafast photodissociation of H2 excited by a femtosecond extreme UV laser pulse.
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Affiliation(s)
- Etienne Gindensperger
- Laboratoire Collisions Agrégats Réactivité, Institut de Recherche sur les Systémes Atomiques et Moléculaires Complexes, Centre National de la Recherche Scientifique -Université Paul Sabatier, Toulouse, France.
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46
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47
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Computation of Reaction Mechanisms and Dynamics in Photobiology. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/s1380-7323(05)80024-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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48
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Roman E, Martens CC. Semiclassical Liouville method for the simulation of electronic transitions: Single ensemble formulation. J Chem Phys 2004; 121:11572-80. [PMID: 15634122 DOI: 10.1063/1.1818122] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this paper, we describe a single ensemble implementation of the semiclassical Liouville method for simulating quantum processes using classical trajectories. In this approach, one ensemble of trajectories supports the evolution of all semiclassical density matrix elements, rather than employing a distinct ensemble for each. The ensemble evolves classically under a single reference Hamiltonian, which is chosen based on physical grounds; for electronic relaxation of an initially excited state, the initially populated upper surface Hamiltonian is the natural choice. Classical trajectories evolving on the reference potential then represent the time-dependent upper state population density and also the electronic coherence and the ground state density created by electronic transition. The error made in the classical motion of the trajectories for these latter distributions is compensated for by incorporating the difference between the correct and reference Liouville propagators into the calculation of the coefficients of the individual trajectories. This approach gives very accurate results for a number of model problems and cases describing ultrafast electronic relaxation dynamics.
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Affiliation(s)
- Eduardo Roman
- Department of Chemistry, University of California, Irvine, California 92697-2025, USA
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49
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Puzari P, Sarkar B, Adhikari S. Quantum-classical dynamics of scattering processes in adiabatic and diabatic representations. J Chem Phys 2004; 121:707-21. [PMID: 15260597 DOI: 10.1063/1.1758700] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We demonstrate the workability of a TDDVR based [J. Chem. Phys. 118, 5302 (2003)], novel quantum-classical approach, for simulating scattering processes on a quasi-Jahn-Teller model [J. Chem. Phys. 105, 9141 (1996)] surface. The formulation introduces a set of DVR grid points defined by the Hermite part of the basis set in each dimension and allows the movement of grid points around the central trajectory. With enough trajectories (grid points), the method converges to the exact quantum formulation whereas with only one grid point, we recover the conventional molecular dynamics approach. The time-dependent Schrodinger equation and classical equations of motion are solved self-consistently and electronic transitions are allowed anywhere in the configuration space among any number of coupled states. Quantum-classical calculations are performed on diabatic surfaces (two and three) to reveal the effects of symmetry on inelastic and reactive state-to-state transition probabilities, along with calculations on an adiabatic surface with ordinary Born-Oppenheimer approximation. Excellent agreement between TDDVR and DVR results is obtained in both the representations.
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Affiliation(s)
- Panchanan Puzari
- Department of Chemistry, Indian Institute of Technology, Guwahati, North Guwahati, Guwahati-781 039, India
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50
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Horenko I, Weiser M, Schmidt B, Schütte C. Fully adaptive propagation of the quantum-classical Liouville equation. J Chem Phys 2004; 120:8913-23. [PMID: 15267827 DOI: 10.1063/1.1691015] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In mixed quantum-classical molecular dynamics few but important degrees of freedom of a dynamical system are modeled quantum-mechanically while the remaining ones are treated within the classical approximation. Rothe methods established in the theory of partial differential equations are used to control both temporal and spatial discretization errors on grounds of a global tolerance criterion. The TRAIL (trapezoidal rule for adaptive integration of Liouville dynamics) scheme [I. Horenko and M. Weiser, J. Comput. Chem. 24, 1921 (2003)] has been extended to account for nonadiabatic effects in molecular dynamics described by the quantum-classical Liouville equation. In the context of particle methods, the quality of the spatial approximation of the phase-space distributions is maximized while the numerical condition of the least-squares problem for the parameters of particles is minimized. The resulting dynamical scheme is based on a simultaneous propagation of moving particles (Gaussian and Dirac deltalike trajectories) in phase space employing a fully adaptive strategy to upgrade Dirac to Gaussian particles and, vice versa, downgrading Gaussians to Dirac-type trajectories. This allows for the combination of Monte-Carlo-based strategies for the sampling of densities and coherences in multidimensional problems with deterministic treatment of nonadiabatic effects. Numerical examples demonstrate the application of the method to spin-boson systems in different dimensionality. Nonadiabatic effects occurring at conical intersections are treated in the diabatic representation. By decreasing the global tolerance, the numerical solution obtained from the TRAIL scheme are shown to converge towards exact results.
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Affiliation(s)
- Illia Horenko
- Freie Universitt Berlin, Arnimallee 2, D-14195 Berlin, Germany.
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