lammps and polymer

What is the best method to simulation of polymer in lammps?
How Can I build data file?
I want to simulate polymers with pcff force field.
I use msi2lmp,but it has many errors!
Thanks

What is the best method to simulation of polymer in lammps?

what kind of polymer?
what do you understand as "best"?

How Can I build data file?

there are many ways. the format is well documented.
there are several tools to generate one.

I want to simulate polymers with pcff force field.

well, that is your choice.

I use msi2lmp,but it has many errors!

so you have an incentive to fix it.
this is how these tools get written
and corrected.

axel.