Organic molecule blows up

Dear lammps users,
Im simulating an organic molecule of P3HT ( that consists of Sulfur, Hydrogen and Carbon)
Im using a forcefield derived from MM3 forcefield.
I double-checked every coefficient especially pair and bond parts, but it kept blowing up (see the attachment)
My bond interactions are way higher than the pair ones so does that mean that the problem is in the bond coefficients?
But they seems right comparing to the paper i got the coefficients from/

With regards, Vasiliy Triandafilidi

lammps_thiophene.rar (10.3 KB)

Dear lammps users,
Im simulating an organic molecule of P3HT ( that consists of Sulfur,
Hydrogen and Carbon)
Im using a forcefield derived from MM3 forcefield.
I double-checked every coefficient especially pair and bond parts, but it
kept blowing up (see the attachment)
My bond interactions are way higher than the pair ones so does that mean
that the problem is in the bond coefficients?
But they seems right comparing to the paper i got the coefficients from/

please check something more simple but equally problematic:
your coordinates or bond definitions could be off, i.e. you bonded
the wrong atoms.

axel.