I would like to seek advice. I am trying to convert Gromacs force field files to LAMMPS files using gro2lam. I found two methods in the software documentation. One method uses the autoload button, but there are several warnings and errors when generating the force field file, such as “Directive bondtypes not found!”; “The bondtypes section is missing on zn top file”; “Type 9 Proper dihedral (multiple) angle style conversion in Fourier form can only be used if LAMMPS was built with the USER-MISC package!!”
I am considering using the second method, which involves selecting the itp files containing the defaults, atomtypes, and bondtypes directives. However, gro2lam requires input for a forcefield file, a non-bonded file, and a bonded file. I only have one itp file and would like to ask what each of these three types of itp files corresponds to.
zn.itp (61.6 KB)
Hello,
This seems more like a GROMACS question, and therefore you are on the wrong forum.
But to answer your question, it is common practice in GROMACS to divide the force field in several files, including a file for all bonded interactions, and another file for all non-bonded interactions. If having all 3 files is really a requirement of gro2lam (?), you can probably divide your files this way, it does not really matter.
Thank you for your response, and I apologize for sending my message to the wrong place. I’m not very familiar with GROMACS, but I initially tried to provide the three types of ITP files required by gro2lam from the same complete ITP file, but I wasn’t able to successfully generate the LAMMPS format force field file. I am now confused about the standard for dividing them into three ITP files
Did you try contacting the authors or gro2lam? Note that converting GROMACS to LAMMPS files and vice versa is not very difficult, and if gro2lam does not work for you, you can still do it manually.