non-reactive reax/c toggle

Dear lammps users,

Sorry to bother you all but I would like to ask if any one knows if there is a toggle available in reaxc module to stop the bond order change thus creating non-reactive steps for reaxff simulations. I have seen in ADF program there is a keyword 'nrstep' introduced to do such a setting, but I can't find any information of a similar toggle in lammps.

Thank you!


Hi Qing,

I don't think it is possible to perform such task in LAMMPS. Maybe
Aidan or Metin may wish to comment if it is easy to make modifications
to reax or reax/c.


Hi Qing,

If I recall correctly, I had implemented such a feature on the serial
version of reax/c (a.k.a. SerialReax) in the early days of development.
However, such a feature is kinda tricky to implement in the parallel
version, as the processor that owns an atom changes over the course of
simulation. Therefore I decided not to include it in the parallel version.

If you are willing to put some effort in implementing this feature, I
can provide suggestions and guidance.


Hi Metin,

I found a hint of such a feature in the standalone reaxff code too. In the outdate parameter section, there is a keyword "nreax" offers option to turn off the reactivity. Checking the source code it seems that turning on this toggle will by pass the bond order evaluation process after calculation bond distances, thus disable the energy contribution from bonding and no bond breaking/formation would take place. I am very glad to hear you have done such a development before too, did you use the similar approach as in the reaxff stand alone code? I would great appreciate it if you can give me some help on bringing this toggle back to the parallel reax/c.