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arXiv · 1401.3033

Kinetically Constrained Ring-Polymer Molecular Dynamics for Non-adiabatic Chemical Reactions

Artur R. Menzeleev·Franziska Bell·Thomas F. Miller III
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Abstract

We extend ring-polymer molecular dynamics (RPMD) to allow for the direct simulation of general, electronically non-adiabatic chemical processes. The kinetically constrained (KC) RPMD method uses the imaginary-time path-integral representation in the set of nuclear coordinates and electronic states to provide continuous equations of motion that describe the quantized, electronically non-adiabatic dynamics of the system. KC-RPMD preserves the favorable properties of the usual RPMD formulation in the position representation, including rigorous detailed balance, time-reversal symmetry, and invariance of reaction rate calculations to the choice of dividing surface. However, the new method overcomes significant shortcomings of position-representation RPMD by enabling the description of non-adiabatic transitions between states associated with general, many-electron wavefunctions and by accurately describing deep-tunneling processes across asymmetric barriers. We demonstrate that KC-RPMD yields excellent numerical results for a range of model systems, including a simple avoided-crossing reaction and condensed-phase electron-transfer reactions across multiple regimes for the electronic coupling and thermodynamic driving force.

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Artur R. Menzeleev, Franziska Bell, Thomas F. Miller III. 2014-01-13. Kinetically Constrained Ring-Polymer Molecular Dynamics for Non-adiabatic Chemical Reactions. https://doi.org/10.1063/1.4863919

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