(no subject)

Hi dear lammps users,
I am preparing the simulation of cellulose by using LAMMPS, and use charmm36 forcefield to describe the interactions between atoms. I have got the PDB and PSF files of my structure, and also the charmm36 top and par files downloaded from http://mackerell.umaryland.edu/charmm_ff.shtml. However, when I want to use charmm2lammps to generate the lammps data and in files, I have problems. The perl script cannot proceed and just stop at the following state:

222_1.pdb (6.54 KB)

top_all36_carb.rtf (286 KB)

222_1.psf (21.1 KB)

par_all36_carb.prm (157 KB)

The core of the charmm2lammps.pl script is very old and was written when CHARMM 19 was the current version of the CHARMM force field.
It has no support for the “EXT” flavor of psf files and atom types with more than 5 characters. Thus it will be able to read the topology, but cannot assign force field types correctly.


Hi Axel,
Thank you very much for helping me. I have just solved the problem, I forgot hitting the enter button…
Best regards