Hi,
I have a question about the “special_bonds” command:
I do MD simulation by TIP4P water model (pair_style lj/cut/tip4p/long) and since I already knew the default of this command is “0.0 0.0 1.0” most of the time I have not used it in the input file!
([lammps-users] Do I need to use special_bonds with water?)
I just checked the default now (special_bonds command — LAMMPS documentation) and I wonder If my presumption is still correct.
The new default is special_bonds lj/coul 0.0 0.0 0.0, so you are good to go with your current settings.
You should explicitly set your desired special_bonds coefficients.
Not only is this necessary in the LAMMPS context (since different versions now have different defaults), this is also important for reproducibility when you eventually publish your results, as it will (hopefully) remind you to specify what settings you used. A force field includes the specification of partial charges, mixing rules, tail corrections, and bond exclusion settings; any publication that doesn’t completely describe them is not reproducible, and should in principle not be published.
Good point. Ensuring the reproducibility of published results is paramount.
That is NOT true. The default for special_bonds has always been “0.0 0.0 0.0” in LAMMPS. Even in the Fortran versions that predate the C++ version of LAMMPS.