  Simultaneous treatment of neutrino oscillations and collisions in
astrophysical environments requires the use of (quantum) kinetic equations.
Despite major advances in the field of quantum kinetics, the structure of the
kinetic equations and their consistency with the uncertainty principle are
still debated. The goals of the present work are threefold. First, it clarifies
the structure of the Liouville term in the presence of mixing. Second, we
derive evolution equation for neutrinos propagating in vacuum or matter from
the Schrodinger equation and show that in the relativistic limit its form
matches the form of the (collisionless part of the) kinetic equation derived by
Sigl and Raffelt. Third, by constructing solutions of the evolution equation
from the known solutions of the Schrodinger equation, we show that the former
also admits solutions consistent with the uncertainty principle and accounts
for neutrino wave packet separation. The obtained results speak in favor of a
(quantum) kinetic approach to the analysis of neutrino propagation in exploding
supernovae where neutrino oscillations and collisions, as well as the effect of
wave packet separation, might be equally important.
