  Recently, Lad, Patel, and Pratap (LP&P) [Phys. Rev. E 105, 064107 (2022)]
revisited a microscopic theory of molecular motion in liquids, proposed by
Glass and Rice [Phys. Rev. 176, 239 (1968)]. Coming from this theory, LP&P
derived a new equation of motion for the velocity autocorrelation function
(VAF) and argued that the friction coefficient of particles in liquids should
exponentially depend on time. The numerical solution of this equation was
fitted to the results of molecular dynamics simulations on different liquids.
In our Comment [Phys. Rev. E 108, 036107 (2023)], we showed that this solution,
obtained under the condition of zero derivative of the VAF at time t = 0, is
physically incorrect. This was evidenced by our exact analytical solution for
the VAF, not found by LP&P, and numerically, by using the same method as in the
commented work. In the Reply [Phys. Rev. E 108, 036108 (2023)], Lad, Patel,
Pratap, and Pandya claimed that our solution does not satisfy all the necessary
boundary conditions and is thus not appropriate for the description of atomic
dynamics in liquids. Until and unless proven otherwise they do not find any
reason for the reconsideration of their theory. Here we give a rebuttal to this
Reply and, returning to the original work by LP&P, show that the presented
there equation for the VAF is wrong. Due to errors in its derivation, it is,
among other inconsistencies, incompatible precisely with the boundary
conditions for the VAF which lie in the basis of their theory.
