  The interaction of moving discrete solitons with a linear Gaussian defect is
investigated. Solitons with profiles varying from hyperbolic secant to
exponentially localized are considered such that the mobility of soliton is
maintained; the condition for which is obtained. Studies on scattering of the
soliton by an attractive defect potential reveal the existence of total
reflection and transmission windows which become very narrow with increasing
initial soliton amplitude. Transmission regions disappear beyond the
small-amplitude limit. The regions of complete reflection and partial capture
correspond to the windows of the existence and nonexistence of solution of the
stationary problem. Interaction of the discrete soliton with a barrier
potential is also investigated. The critical amplitude of the defect at which
splitting of the soliton into two parts occurs was estimated from a balance
equation. The results were confirmed through direct numerical integration of
the dynamical equation showing very good agreement with the analytical
prediction.
