How to make a data file for a polymer structure based on pcff force field to use in lammps

Hi,

I have a general question.

I know one easy method to make a data file for a polymer with pcff force field. This method is building the structure in Materials Studio, then assigning the pcff/cvff/compass force field using Discover Module. Finally using msi2lmp.exe we can make the data file for lammps.

However, for those who do not have access to Materials Studio and Discover Module, how can they assign the pcff force filed to the built polymer structure and make the corresponding data file? What are the alternative procedures for this job?

Thank you.

If you don’t have Materials Studio, I thought you also did
not have access to their proprietary force fields?

If you do have a publicly available force field file,
Axel can comment on how/if you could use it with msi2lmp.

I presume you will have to devise some way to come
up with what you call the “built polymer structure”, to input

it to msi2lmp the way it expects. However, if that were easy for general

polymer structures, then tools like Materials Studio wouldn’t
be necessary …

Steve

I should add that you look at the LAMMPS web page:

http://lammps.sandia.gov/prepost.html

for a discussion of alternate builders.

Steve

If you don’t have Materials Studio, I thought you also did
not have access to their proprietary force fields?

If you do have a publicly available force field file,
Axel can comment on how/if you could use it with msi2lmp.

Actually msi2lmp ships with some published parameter force field files.

Try using Xenoview (I think it is free). I haven’t used it but have heard about it. It has a builder and some published force-field parameters. You can import your molecule there and assign PCFF force field (basically atomtypes) and save in mdf car format. Probably worth a shot.

Good luck.
Vikas