  The study of chemical reactions in environments under nonequilibrium
conditions has been of interest recently in a variety of contexts, including
current-induced reactions in molecular junctions and scanning tunneling
microscopy experiments. In this work, we outline a fully quantum mechanical,
numerically exact approach to describe chemical reaction rates in such
nonequilibrium situations. The approach is based on an extension of the flux
correlation function formalism to nonequilibrium conditions and uses a mixed
real and imaginary time hierarchical equations of motion approach for the
calculation of rate constants. As a specific example, we investigate
current-induced intramolecular proton transfer reactions in a molecular
junction for different applied bias voltages and molecule-lead coupling
strengths.
