Repository logo
 

A mapping variable ring polymer molecular dynamics study of condensed phase proton-coupled electron transfer.

Accepted version
Peer-reviewed

Type

Article

Change log

Authors

Pierre, Sadrach 
Duke, Jessica R 
Hele, Timothy JH 
Ananth, Nandini 

Abstract

We investigate the mechanisms of condensed phase proton-coupled electron transfer (PCET) using Mapping-Variable Ring Polymer Molecular Dynamics (MV-RPMD), a recently developed method that employs an ensemble of classical trajectories to simulate nonadiabatic excited state dynamics. Here, we construct a series of system-bath model Hamiltonians for the PCET, where four localized electron-proton states are coupled to a thermal bath via a single solvent mode, and we employ MV-RPMD to simulate state population dynamics. Specifically, for each model, we identify the dominant PCET mechanism, and by comparing against rate theory calculations, we verify that our simulations correctly distinguish between concerted PCET, where the electron and proton transfer together, and sequential PCET, where either the electron or the proton transfers first. This work represents a first application of MV-RPMD to multi-level condensed phase systems; we introduce a modified MV-RPMD expression that is derived using a symmetric rather than asymmetric Trotter discretization scheme and an initialization protocol that uses a recently derived population estimator to constrain trajectories to a dividing surface. We also demonstrate that, as expected, the PCET mechanisms predicted by our simulations are robust to an arbitrary choice of the initial dividing surface.

Description

Keywords

0306 Physical Chemistry (incl. Structural)

Journal Title

J Chem Phys

Conference Name

Journal ISSN

0021-9606
1089-7690

Volume Title

147

Publisher

AIP Publishing