The treatment in Problem 20.28 applies only to one-dimensional solids. In three dimensions, the variation of density

Question:

The treatment in Problem 20.28 applies only to one-dimensional solids. In three dimensions, the variation of density of states is more like that shown in Fig. 20.70. Account for the fact that in a three-dimensional solid the greatest density of states lies near the centre of the band and the lowest density at the edges.

p-band s-band Density of states, p Energy