Journal Article10.1039/B314253A
A novel algorithm for non-adiabatic direct dynamics using variational Gaussian wavepackets
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TL;DR: This work presents the first direct dynamics calculations using a novel algorithm, based on the powerful multi-configuration time-dependent Hartree (MCTDH) wavepacket propagation method, that provides a feasible direct dynamics algorithm for the description of this non-adiabatic process.
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Abstract: In a recent paper (G. Worth, P. Hunt and M. Robb, J. Phys. Chem. A, 2003, 107, 621), we used surface hopping direct dynamics calculations to study the molecular dynamics of the butatriene radical cation in the /A manifold, which is coupled by a conical intersection. Here, we present the first direct dynamics calculations using a novel algorithm, again using this ideal test system. The algorithm, which is based on the powerful multi-configuration time-dependent Hartree (MCTDH) wavepacket propagation method, uses a variational basis of coupled frozen Gaussian functions that optimally represent the evolving nuclear wavepacket at all times. Each Gaussian function follows a “quantum trajectory”, along which the potential surface is evaluated by quantum chemistry calculations. As far fewer Gaussian functions are needed than classical trajectories in a semi-classical method, the number of quantum chemical calculations is drastically reduced. A crucial point in direct dynamics. To validate the method, initial calculations have been made using an analytic model Hamiltonian, where it is shown to reproduce the main features of the state population transfer with 8–16 basis functions per state. Coupled to the GAUSSIAN quantum chemistry program, the method is then shown to provide a feasible direct dynamics algorithm for the description of this non-adiabatic process.
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Citations
Ab Initio Nonadiabatic Quantum Molecular Dynamics.
TL;DR: A review of methods that can describe nonadiabatic dynamics in molecules, with emphasis on those that are able to simultaneously address the quantum mechanics of both electrons and nuclei.
Modeling the Kinetics of Bimolecular Reactions
Antonio Fernández-Ramos,James A. Miller,Stephen J. Klippenstein,Stephen J. Klippenstein,Donald G. Truhlar +4 more
TL;DR: This review is concerned with the theoretical and computational modeling of bimolecular reactions, especially with generally applicable methods for kinetics (i.e., overall rates as opposed to detailed dynamics), and includes a basic theoretical framework that can be used for gas-phase thermal reactions, gas- phase microcanonical and state-selected reactions, and condensed-phase chemical reactions.
617
SHARC: ab Initio Molecular Dynamics with Surface Hopping in the Adiabatic Representation Including Arbitrary Couplings
TL;DR: A semiclassical surface-hopping method which is able to treat arbitrary couplings in molecular systems including all degrees of freedom is presented, in very good agreement with those calculated from exact quantum dynamical simulations.
488
Role of Conical Intersections in Molecular Spectroscopy and Photoinduced Chemical Dynamics
Wolfgang Domcke,David R. Yarkony +1 more
TL;DR: This review describes how conical intersections affect measured molecular spectra and simple photofragmentation processes, and considers excitations that result in electron ejection or photodetachment, as well as photoinduced H-atom elimination.
481
Mixed Quantum Mechanical/Molecular Mechanical Molecular Dynamics Simulations of Biological Systems in Ground and Electronically Excited States
TL;DR: By using feature selection algorithms to identify the most appropriate subset of relevant variables that describe a certain phenomenon, the high-dimensionality of QM/MM data can be reduced and used for further analysis with causal inference algorithms to establish unique cause-effect relationships.
432
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