Writing LAMMPS data file missing mass-type relationship
When writing an ASE atoms object to LAMMPS data format, it appears that the "Masses" block that maps atom type to mass (example below) is not written, forcing the user to assign per-type masses in a LAMMPS script instead.
Masses
1 mass
...
N mass (N = # of atom types)
I am by no means an ASE or LAMMPS expert, but I believe this is the case. I have checked the source code for write_lammps_data
and found no code that would perform such a write, and no instances of "mass".
This does not seem like a difficult addition since ASE should already have the necessary info, but perhaps I am using ASE improperly and/or missing a legitimate reason it is not implemented.
If it just hasn't been implemented yet, please let me know, and I will make a pull request unless somebody else knows they can/will get it done faster.