  Various regimes of a charge motion along a chain in a constant electric field
are investigated. This motion is simulated on the basis of the Holstein model.
Earlier studies demonstrate a possibility of a uniform motion of a charge in a
constant electric field over very long distances. For small values of the
electric field intensity a Holstein polaron can move at a constant velocity. As
the electric field intensity increases, a charge motion acquires oscillatorily
character, performing Bloch oscillations. Since the charge motion depends on
the whole set of the system parameters the character of the motion depends not
only on the value of the electric field intensity. Therefore, the electric
field intensity for which the uniform motion takes place differs for chains
with different parameters. The character of the charge motion and distribution
is considered in chains with different values of the constant of coupling
between the charge and the displacements of the chain. It is shown that the
values of the electric field intensity for which the regime of a charge motion
changes are different in chains with different values of the coupling constant.
It is also demonstrated that for one and the same value of the electric field
intensity, in chains with different values of the coupling constant either a
uniform motion or an oscillatory motion, or a stationary polaron can be
observed.
