Tersoff usage

Dear LAMMPS users,

I am sorry for asking easy and stupid question because I am really new user. I am trying to perform test simulation of SiO2 using tersoff potential. However, I received the calculation values all NAN values as follows: (First step and the last step values.) Do you have any advice?

Per MPI rank memory allocation (min/avg/max) = 9.009 | 9.009 | 9.009 Mbytes
---------------- Step 0 ----- CPU = 0.0000 (sec) ----------------
TotEng = -nan KinEng = 466.2823 Temp = 298.1500
PotEng = -nan E_bond = 0.0000 E_angle = 0.0000
E_dihed = 0.0000 E_impro = 0.0000 E_vdwl = -nan
E_coul = 0.0000 E_long = 0.0000 Press = -nan

---------------- Step 10000 ----- CPU = 91.9794 (sec) ----------------
TotEng = -nan KinEng = -nan Temp = -nan
PotEng = -nan E_bond = 0.0000 E_angle = 0.0000
E_dihed = 0.0000 E_impro = 0.0000 E_vdwl = -nan
E_coul = 0.0000 E_long = 0.0000 Press = -nan
Loop time of 91.9794 on 1 procs for 10000 steps with 12100 atoms

I also copied my input files.
input script

Dear LAMMPS users,

I am sorry for asking easy and stupid question because I am really new user. I am trying to perform test simulation of SiO2 using tersoff potential. However, I received the calculation values all NAN values as follows: (First step and the last step values.) Do you have any advice?

before posting to the mailing list, you should research previous questions and answer to similar problems in the mailing list archive.
this case appears regularly, so there should be plenty of answers and advice available already.

axel.