When asking about situations where you get error, please always report which LAMMPS version you are using, what platform you are on and - ideally - provide a minimal input deck that can reproduce the error. This will help enormously to provide correct and meaningful advice.
It sounds about right. At least for the current LAMMPS release version.
If you don’t want to include charges, you need to use atom_style hybrid edpd molecular (or build a hybrid with angle or bond if you don’t need dihedrals and impropers, or also don’t need angles). Otherwise the charge data must be present in the data file. Whether data must be present is determined by the atom style; whether it is used is determined by the pair style (and bond/angle/dihedral/improper style etc.).
No. At least not in recent version.
It would really help to see an example that produces the error.
This one works for me for atom_style hybrid edpd fullwith charges , for example:
Thank you so much for your quick and explanatory reply. my lammps version is LAMMPS (29 Sep 2021 - Update 3). I will try the format you told me. I’m editting my question to include some part of the data file.
Check your file very carefully. LAMMPS requires that all input is using ASCII characters.
There are non-ASCII characters (in UTF-8 encording) that look exactly or almost the same. This applies to blanks, too. If they are not ASCII characters, LAMMPS may not be able to correctly parse such files.
Thanks a lot akohlmey. What do you recommend to modify the data file? I modified my data file from VMD with excel but saving it as text it seems it changes the format. Is there any better way to modify data files without messing up with it?
You have to use the tools that you are familiar with and then just make sure you use them correctly and request the correct changes.
There are many different ways to introduce additional or move existing columns. I probably would do this with the emacs text editor, because that is what I am most familiar with and that has a functionality for cutting and pasting rectangular regions. If I had to work on a machine where emacs is not available, I would probably split the file into 3 segments (1: up to and including the Atoms keyword, 2: the Atoms section w/o the header, 3: after the Atoms section), then process the middle section with either “awk” or “perl” or “python”, and then paste this modified middle section together with the preserved first and last section.