It should be noted that
< EF. This does not limit the applicability of (
N  was calculated for simplicity for
6.11), however, since the
T ! If the highest filled s-band of a crystal is
occupied by two electrons per atom, i.e., if the band is completely filled,
we would expect that the electrons cannot drift through the crystal when an
external electric field is applied (as it is similarly impossible to move a car in
a completely occupied parking lot).6.6.6.7(a)).6.7(b)).