the system has no change after simulation

Hi,everyone.
I am new to lammps. I have a problem that after using minimize command to optimize the model , the system has no change in energy .In addition, the gas molecules and other atoms seem to stand still. Something should have happened.But it didn’t.Temperature is kept at 1100K using Berendsen thermostat and the thermo result is also 1100K. I can’t find the problem and have no idea what I can do next.I need some help!!! Thank you for your time reading my letter and appreciate your comment.
P.S. The following is my input file.

units real

boundary s s s

atom_style full
read_data data.gnh3

pair_style reax
pair_coeff * * ffield.reax 1 3 2

minimize 1.0e-8 1.0e-6 5000 5000
min_style cg

group 1 type 1 2 3
group H type 3

velocity 1 create 1100.0 554654

fix 1 1 temp/berendsen 1100.0 1100.0 100.0
compute T 1 temp/com
fix_modify 1 temp T

compute EOH H ke

dump cut 1 atom 200 *.lammpstrj
dump_modify cut sort id pad 5

restart 3000 restart.*.lammpstrj

thermo 200
thermo_style custom step temp etotal ke pe c_EOH

timestep 1.0

run 6000

Best wishes
Zongyang Qiu
07-22-2012

Hi Luoyuan,

See the "IMPORTANT NOTE" of the fix temp/berendsen doc page:
http://lammps.sandia.gov/doc/fix_temp_berendsen.html

You need a fix nve to do time integration.

Also, you use just "atom_style charge" for reax and reax/c.

Best,
Ray