fix nphug

Dear All,
I am using LAMMPS (14 Feb 2014) and have some questions about fix nphug command:
Although I have run the simulation up to 2000000 steps, the temperature still rode up and the volume still decrease slowly, I don’t know why.
Some mainly settings of mine are as below:
atom_style eam/fs
timestep 0.001 #timestep=0.001ps
fix myhug all nphug temp 300.0 300.0 0.1 z 150000 150000 1.0
fix_modify myhug energy yes

Thank you very much for your answer.
Best regards,

Aidan or Ray may be answer Qs about nphug.

Steve

Lots of possible reasons for slow drift. Try examining the sensitivity to the timestep.