[lammps-users] question for NVT

Dear all,

I have a question in using LAMMPS. When I run a MD about GaN crystal, I have set the system ensemble as NVT, I have set the temperature 300K initially. But in the log system, the temperature is not the constant as I have set, I am so confused about the temperature setting. The following is the parameter in my input file and the temperature in my log file. Could you give me some suggestions about this problem? I will appreciate it.

The parameter for NVT in my input file:

minimize 1.0e-4 1.0e-6 1000 1000

fix 2 all nvt 300.0 300.0 100.0

dump 2 all xyz 100 dump.crystal

run 1000000

The data in my log file:

Step Temp E_pair E_mol TotEng Press

21 0 -5663.9367 0 -5663.9367 251520.45

1000 2.080412 -5664.3043 0 -5663.9367 251245.27

2000 4.8563314 -5664.7947 0 -5663.9366 250720.75

3000 3.8455842 -5664.6158 0 -5663.9363 250703.3

4000 2.1073358 -5664.3082 0 -5663.9359 250859.59

………

999000 3.3311556 -5808.2308 0 -5807.6422 222726.48

1000000 3.3909705 -5808.2229 0 -5807.6237 222739.35

1000021 3.3674552 -5808.2183 0 -5807.6233 222726.5

I have also try to minimize first and then run, but the result is similar that the T is not over 300K

Regards,

Xiaojing Gong