  We establish the exact low-energy asymptotics of the integrated density of
states (Lifschitz tail) in a homogeneous magnetic field and Poissonian
impurities with a repulsive single-site potential of Gaussian decay. It has
been known that the Gaussian potential tail discriminates between the so-called
"classical" and "quantum" regimes, and precise asymptotics are known in these
cases. For the borderline case, the coexistence of the classical and quantum
regimes was conjectured. Here we settle this last remaining open case to
complete the full picture of the magnetic Lifschitz tails.
