  We theoretically study nonadiabatic corrections for charge pumping in a
noninteracting electron model of a single-level quantum dot. We derive a
formula for the velocity limit of parameter driving to realize adiabatic
pumping and illustrate its features in the wide-band limit. We discuss the
effect of the nonadiabatic corrections in terms of a typical velocity limit,
which is defined by averaging the velocity limits on the parameter contour. We
also show that the typical velocity limit vanishes when the adiabaticity
breakdown occurs in a quantum dot coupled to reservoirs with a band edge.
