  Atoms, propagating across a detuned standing laser wave, can be scattered in
a chaotic way even in the absence of spontaneous emission and any modulation of
the laser field. Spontaneous emission masks the effect in some degree, but the
Monte Carlo simulation shows that it can be observed in real experiments by the
absorption imaging method or depositing atoms on a substrate. The effect of
chaotic scattering is explained by a specific behavior of the dipole moments of
atoms crossing the field nodes and is shown to depend strongly on the value of
the atom-laser detuning.
