Formula for field dependent mobility

For semiconductor material, there are many field dependent mobility model. It is hard to get one equations fitted with all materials. Hence, the field dependent mobility model is case dependent. Usually it can be described by model fitting. However, we still define some equations that people proposed to be used in DDCC. 
For 2D-DDCC, the field dependent mobility model can be defined by different type 

type: 1

$v = \frac{\vec{E} p_{1} + p_{2} \left(  \frac{\vec{E}}{p_{3}}  \right)^{p_4}  }{ 1+ \left( \frac{\vec{E}}{p_{3}}  \right)^{p_{4}} + p_{5}\left( \frac{\vec{E}}{p_{3}}  \right)^{p_{6}}  }$
$\mu = v / |\vec{E}|$