Comments on a paper by Straub, Borkovec, and Berne

The paper referred to in the title, in J. Chem. Phys. 84, 1788 (1986), presented results of computer simulations of non-Markovian barrier crossing dynamics, and compared these results with various theoretical predictions. One comment made here is that the observed limited applicability of the Grote–Hynes theory can be explained by singular perturbation theory. The other comment concerns the importance of a second constant of the motion when the non-Markovian friction has a very long relaxation time.