[gmx-users] difference between gmx energy and gmx traj

[Ray Chao]

Hi, All,

I ran a NVT simulation for a water sphere with position restraint. The
TIP4P water model was used. I tried to relax the system at temperature of
300K.  After the simulation, I used gmx energy to cal the system
temperature and it is around 300K. However, when I tried to use gmx traj to
extract the temperature from "SOL" group, the temperature is always half of
that calculated from gmx energy. Is there any difference between these two
commands? Or is there any other way to determine the temperature of each
group?

Thank you very much.

Best regards,
Lei Zhao