  I show that the theory developed for quantum delocalization of an excited
Hydrogen atom in a two-frequency linearly polarized microwave field can be used
with a few adaptions to explain the quantum delocalization of Alkali atoms in a
linearly polarized monochromatic field in the regime where it deviates from
Hydrogenic behaviour. Comparison with numerical and laboratory experiments is
satisfactory: apart from a constant factor, independent from the microwave
frequency, the same dependence from the initial quantum number is observed.
