Electronic and nuclear flux analysis on nonadiabatic electron transfer reaction: A view from single‐configuration adiabatic born–huang representation

Phys. Chem. Chem. Phys.

2020

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Section: Computational Methodologymentioning

confidence: 99%

Charge separation and successive reconfigurations of electronic and protonic states in a water-splitting catalytic cycle with the Mn₄CaO₅ cluster. On the mechanism of water splitting in PSII

Yamamoto

Phys. Chem. Chem. Phys.

2020

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“…Many applications of electron flux in chemical dynamics have been reported. − Incidentally, the present work treats only the electronic flux at each nuclear configuration. Manz and his group have been studying the total electronic and nuclear flux. ,, One of the latest comprehensive descriptions of the electronic and nuclear fluxes to analyze nonadiabatic dynamics in the Born–Huang representation has been given by Matsuzaki and Takatsuka. , …”

Section: Methodsmentioning

confidence: 99%

“…The box of each panel highlights which proton is involved in the inverse CPEWT or CPEWT. Note that electron flux j ( r , t ) can oscillate with less than 1.0 fs of frequency, and the net electron transfer is represented by integrating them over space-time (see refs , for a general discussion about oscillatory behavior of electron flux).…”

Section: Molecular Materialization Of the Abstract Modelsmentioning

confidence: 99%

On the Elementary Chemical Mechanisms of Unidirectional Proton Transfers: A Nonadiabatic Electron-Wavepacket Dynamics Study

Yamamoto

2019

J. Phys. Chem. A

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We propose a set of chemical reaction mechanisms of unidirectional proton transfers, which may possibly work as an elementary process in chemical and biological systems. Being theoretically derived based on our series of studies on charge separation dynamics in water splitting by Mn oxides, the present mechanisms have been constructed after careful exploration over the accumulated biological studies on cytochrome c oxidase (CcO) and bacteriorhodopsin. In particular, we have focused on the biochemical findings in the literature that unidirectional transfers of approximately two protons are driven by one electron passage through the reaction center (binuclear center) in CcO, whereas no such dissipative electron transfer is believed to be demanded in the proton transport in bacteriorhodopsin. The proposed basic mechanisms of unidirectional proton transfers are further reduced to two elementary dynamical processes, namely, what we call the coupled proton and electron-wavepacket transfer (CPEWT) and the inverse CPEWT. To show that the proposed mechanisms can indeed be materialized in a molecular level, we construct model systems with possible molecules that are rather familiar in biological chemistry, for which we perform the ab initio calculations of full-dimensional nonadiabatic electron-wavepacket dynamics coupled with all nuclear motions including proton transfers.

“…(For molecular flux, see ref. [66][67][68].) With the flux one can directly track the electron flow in molecules as chemical dynamics proceeds.…”

Section: Some Characteristics Of Electron Wavepacket Dynamicsmentioning

confidence: 99%

Time-dependent variational dynamics for nonadiabatically coupled nuclear and electronic quantum wavepackets in molecules

2021

Eur. Phys. J. D

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We propose a methodology to unify electronic and nuclear quantum wavepacket dynamics in molecular processes including nonadiabatic chemical reactions. The canonical and traditional approach in the full quantum treatment both for electrons and nuclei rests on the Born–Oppenheimer fixed nuclei strategy, the total wavefunction of which is described in terms of the Born–Huang expansion. This approach is already realized numerically but only for small molecules with several number of coupled electronic states for extremely hard technical reasons. Besides, the stationary-state view of the relevant electronic states based on the Born–Oppenheimer approximation is not always realistic in tracking real-time electron dynamics in attosecond scale. We therefore incorporate nuclear wavepacket dynamics into the scheme of nonadiabatic electron wavepacket theory, which we have been studying for a long time. In this scheme thus far, electron wavepackets are quantum mechanically propagated in time along nuclear paths that can naturally bifurcate due to nonadiabatic interactions. The nuclear paths are in turn generated simultaneously by the so-called matrix force given by the electronic states involved, the off-diagonal elements of which represent the force arising from nonadiabatic interactions. Here we advance so that the nuclear wavepackets are directly taken into account in place of path (trajectory) approximation. The nuclear wavefunctions are represented in terms of the Cartesian Gaussians multiplied by plane waves, which allows for feasible calculations of atomic and molecular integrals together with the electronic counterparts in a unified manner. The Schrödinger dynamics of the simultaneous electronic and nuclear wavepackets are to be integrated by means of the dual least action principle of quantum mechanics [K. Takatsuka, J. Phys. Commun. 4, 035007 (2020)], which is a time-dependent variational principle. Great contributions of Vincent McKoy in the electron dynamics in the fixed nuclei approximation and development in time-resolved photoelectron spectroscopy are briefly outlined as a guide to the present work.