  We investigate hydrodynamic instability of accelerating ionization fronts
using two dimensional hydrodynamic simulations that include detailed energy
deposition and release due to the absorption of UV radiation, recombination of
hydrogen, radiative molecular cooling, and magnetic pressure. We consider
linear perturbation growth and find that the stabilization mechanism associated
with non-accelerated fronts remains a significant factor even when acceleration
is present. Conversely, if recombination in the ionized region is turned
off,Rayleigh-Taylor (RT) instability becomes effective, and the classical RT
growth rate recovered.
