Dear Lammps users,
I want to employ the reax forcefild “ffield.reax.cho” for a system of hydrocarbons.
I have noticed that I should use the relevent term in fixd qeq/reax too.
In lammps examples it used fix 2 all qeq/reax 1 0.0 10.0 1.0e-6 ““param.qeq””.
While I have seen in some examples it uses fix 2 all qeq/reax 1 0.0 10.0 1.0e-6 “”“reax/c”"".
, I appreciate it if someone could explain which one is relevant for my system and force field??
And one more question , Is there a manual for haw to use mol_frac.c?
Thanks in advance
Simin
In param.qeq you provide parameters as per your choice while in reax/c it takes from force field file.
Dear Lammps users,
I want to employ the reax forcefild “ffield.reax.cho” for a system of hydrocarbons.
are you studying combustion?
I have noticed that I should use the relevent term in fixd qeq/reax too.
In lammps examples it used fix 2 all qeq/reax 1 0.0 10.0 1.0e-6 ““param.qeq””.
While I have seen in some examples it uses fix 2 all qeq/reax 1 0.0 10.0 1.0e-6 “”“reax/c”"".
, I appreciate it if someone could explain which one is relevant for my system and force field??
the meaning of all settings is described in the documentation of fix qeq/reax.
which one is correct and what settings are needed, you need to figure out from the publication describing the force field.
also, please keep in mind, that ReaxFF parameters have limited transferability, i.e. you cannot apply parameters optimized for combustion conditions for a condensed system and vice versa.
thus it is crucial to carefully study the relevant literature before even considering doing simulations with LAMMPS let alone worry about charge equilibration settings.
And one more question , Is there a manual for haw to use mol_frac.c?
what is the source of this file? there is no file in the current LAMMPS distribution.
axel.
Mol_fra.c, located in LAMMPS/tools/reax, is used to analyze output from “fix reax/c/bonds”. Please see README.txt for more information.