TAUW

This command is only needed if the user is using the simplified MEP model for electrons. Indeed, in this case the relaxation time approximation for the electrons energy can be equal to zero (as the reader can see from the definition of the function $\tau_W$ ) comporting the presence of NaN. This is avoided by specifying a value for $\tau_W$ that will be used in the case it is equal to zero. The command is invoked as it follows

 TAUW value

where $value$ is the value specified. Usually a good value is $0.4$ picoseconds. We report an example

 TAUW 0.4e-12

As the reader can see from the example, the unit of measure is the second.