Show that the Bloch function given in Equation (6.1) meets the requirement that the electron density, (r) = 2 (r) = * (r)(r),

Show that the Bloch function given in Equation (6.1) meets the requirement that the electron density, ρ(r) = ψ²(r) = ψ^*(r)ψ(r), must be periodic according to Equation (6.2).

Equation (6.1)

Equation (6.2)

w(r) = ekru(r)