[lammps-users] carbon nanotube modeling

Dear friends

I am a bit confused. I want to calculate Elastic props. of a CNT and I
know the steps, but I can not model them correctly. I am explaining
the steps and my understanding respectively. Please correct me
wherever neccesary.

1-relaxing the initial configuration to reach the equilibrium state:
for this purpose I used "fix nve" along with "setforce 0.0 0.0 0.0"
and after 1000 runs I unfixed it (I'm not sure if it is correct to
relax cnt)

2-fixing boundary condition at one end of the tube:
for this one I did use "fix npt" at all lenght of nanotube except at
the "end group".
(I'm not sure if it is a correct way to put displacement constraint in the end,
How much is suitable for Pdamp?)

3-applying the tension along the axial direction:
for this stage, I used "fix deform". and use strain rate of 0.01.

4-relaxing the CNTs to reach a new equilibrium state while keeping the
two ends constrained:
(Can I constrain the beginig of the tube just by unfixing "fix npt"
command on it?
How should I relax it for 1 psec. for example after one displacement?
should I use minimization command to relax it after each time I deform