We believe that Viščor has misunderstood our work on Meyer-Neldel Rule (MNR). We explain why MNR must always be observed when the activation energy of an activated process is much larger than the energies of the excitations in a thermal bath and much larger than kT, whether or not other physical effects cause the prefactor of the activation term to vary with activation energy. We then point out that recent work on polaron hopping yields results which are consistent with our point of view.

• Received 6 February 2001

DOI:https://doi.org/10.1103/PhysRevB.65.077202