Charged systems with ReaxFF

Dear all,

We would like to follow up on a question asked on 31st May 2011 relating to overall charged system with ReaxFF. Please see the mail below for reference.

"Dear all,
Is it possible to specify the total charge on the system, using either the reax or reax/c pair style? I would like the charge equilibration to optimize the charges under the constraint that the total charge of the system equals, say, +1. This is very easily done in the serial ReaxFF code (using the MOLCHARGE keyword), but I haven't been able to find out how to do it in LAMMPS."
Sequel to this question a reply was given by Steve and referred to Aidan who stated that the code needs to be change.  Please see comment below:
"That is not currently supported in pair_style reax, nor reax/c (I think). It could be done with some minor modifications to the code".
We would also like to set the overall charge of the system to a non-zero value, so we can compare with QM calculations that are also non-zero.  We assume the we need to modify the fix_qeq_reax.cpp file but we are wondering if you could point us to the part of the code or variable that needs to be changed. Any further information which you could give would be highly appreciated.

We look forward to receiving a reply soon.

Many thanks,
'Seun Oyetade
1 Like