Simulation of polymer

Dears
Hope you are fine
I want to make a simulation of polydimethylsiloxane using lattice fcc but I don’t know how i choose the correct lattice constant and also similar input script for polymer simulation including bond, angle and dihedral command without creating data file.
Thanks for your help

You have been asking about this before. When you repeat a question at the very least you should explain why this matters so much to you and why the previous answer(s) were not satisfactory.

I don’t think the lattice command is suitable to build polymers (or at least, I am not so fluent with scripting in LAMMPS). Alternatively, try with Moltemplate, here is a neat example of how to build a single polymer chain. Then you can use the LT file of a single chain to build a more complex sample.