how to modify tersoff.zbl potential file

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1

Dear All:

Now i am working with LAMMPS to simulate the ion bombardement of Silicon(target) with gallium particles(more than one).And now i have some problems in setting force fields of tersoff.zbl potential.

I set the Si atoms as type 1,and set Ga as type 2.I plan to use tersoff/zbl potential for Si-Si interactions and Ga-Ga interactions,and zbl potential for Si-Ga .For pure Ga-Ga interactionswith tersoff.zbl potential ,I have the parameters which is provided in the format of the potential file.

Ga Ga Ga 1.0 1.0 0.0 7.6298e-1 1.9796e1 7.1459e-1 3.47290 2.3586e-1 1.7154 1.14786e2 2.8 .1 3.2834 2.83982e3 31 31 .95 14

Now my problem is that I do not know how to add these parameters to the potential file .Or I just add these parameters in the tersoff.zbl potential file .Best regards.

2

Since Tersoff requires 8 entries for a binary material, you would have to create the rest 6 entries, namely abb, aba, aab, baa, bba, bab., where a is Si and b is Ga. See SiC.tersoff for reference.

3

In anywhere, If I change the parameters in the potential file, I will get a new potential and, the result in simulation when use it to run is different with the result with initial file. How can I decide that potential is right or wrong?

BR,
Phong

4

That’s not a LAMMPS Q. Its barely even an MD question.
You’ll need to read textbooks or the literature.

Steve