$negfionizedimpurity

$negfionizedimpurity is the command to setup the related parameters of ionized impurity scattering.
The equation of ionized impurity scattering:

 $W_{imp}(k)=4\pi F(\frac{2k}{\lambda})^{2}[\frac{1}{\sin^2(\frac{\theta}{2})+(\frac{\lambda}{2k})^2}]^{2}$

 $F=\frac{1}{\hbar}[\frac{Ze^{2}}{\epsilon}]^{2}\frac{N_{1D}(E_{k})}{32k^{4}}N_{I}$

Example:

$negfionizedimpurity
1.0e24 1.0e0 300 400
# NdSD NdC Channeli Channelf

In this case we have 681 mesh grids from drain(left) to source(right), and the position of channel is from 300 to 400. The doping concentration for source and drain is $1*10^{24}(1/m^2)$, and that for channel is $1*10^{0}(1/m^2)$.