KAPPA Example Velocity Scale

Hi All,
Why is it necessary to use the command “velocity all scale $t” in the NEMD example seen in the KAPPA folder?



It is necessary to bring the temperature exactly to the desired value before start the NVE run. Even with a NVT run before the NVE, the final T can be a little bit different to the desired one due to fluctuations.


I think it is not needed. If the system has been equilibrated well, the instant temperature right before the NVE run is allowed to be different from the target. Without such re-scaling, the average temperature in the NVE run should be the target.