Hello,
I prepared my polymer in Materials Studio. I used the Compass2 forcefield. Then I’ll convert it to .data format. My questions are:
1- Should I type msi2lmp.exe KAPTON -class 2 -frc compass2 in the cmd window? If so, I don’t have compass2 in the lammps library. I found compass and solved it with it.
2- When I tried this: msi2lmp.exe KAPTON -class 2 -frc compass, I got the error “Get force field parameters for this system. Unable to find mass for c3ae.” They tell me to change the .car file to c3ae, how do I do this? Is there c3ae directly in compass2.frc?
Could you help? Thanks
Please note that the core of the msi2lmp software is about twenty years old was written for the version of Materials Studio available at that time. Since then changes were made to update it for more recent versions of MS. It has been effectively unmaintained for the last ten years, too.
As open source software, LAMMPS can only bundle force field files with published parameters not encumbered with a commercial license. Most force field parameters bundled with commercial software like Materials Studio are proprietary, and thus you would have to use the force field files that come with your copy.
Who is they?
How should we know? It is you that should have access to that file since you have the MS license.
So what should I do?
Talk to people that have experience with translating simulations from Materials Studio to LAMMPS. The LAMMPS developers don’t. Most of us cannot afford such expensive software and we do our work with LAMMPS directly. Hence the poor state of msi2lmp.