Problem when creating PDMS polymers in moltemplate


I am planning to use lammps to simulate the sliding of PDMS on a surface. But I already got some problems when building the system: I tried to use moltemplate to create PDMS polymer molecules, which I see as a three-part structure consisting of si o and ch3. The ch3 I found described in the compass force field and used it directly (, I was able to get the output file after running it and in ovito I can see that the molecules are there. But running it in lammps is always unsuccessful, first it says empty line in bond coeff, then after I modify it, it says Did not assign all atoms correctly.

I think this is most likely caused by the fact that I wrote the force field incorrectly. However, I lack enough chemistry background to fully figure out these details, so I’m looking for your help.

As a new user I cannot upload any files so I put the inputs of moltemplate here: