Dear all:
I am a freshman for lammps，in the manual （p.471）said the formatted for “fix qeq/reax” as following： itype chi eta gama 。I want to specific the parameters from the article （J. Phys. Chem. 1991,95,3358-3363）for Oxide atom 。 The parameters is in the picture。The param.qeq files ： 1 8.741 13.364 0.669 （Is that true?）
Thank you ！
Yours
Shuaiwei Wang
Maybe Aidan or Metin can answer this.
Steve
Just look at the examples we have provided in the potentials directory,
compare to the papers and you will know. note the comment "eta is defined
here as twice the eta value
in the ReaxFF file."
Aidan
Dear Shuaiwei,
Yes, you are using the parameters in that table in the correct order for param.qeq file. There is no need to multiply the eta parameter by 2 for the values in this table.
The convergence problem you mentioned in your other email might still be related to the qeq parameters, though. A few suggestions:
First of all, make sure that itype matches the atom types in your data file.
Some commonly used parameter sets for oxygen are as follows:
8.5000 16.6244 1.0898
8.5000 14.2824 0.8712
Please give those a try and see if that takes care of the convergence problem.
Thanks,
Metin