Creating Tersoff

Dear All,
Hi

I found the Tersoff potential parameters for N atoms. Now I want to create a .Tersoff file which includes parameters between N, C, H atoms. Does anybody know how can I derive R parameter and create this file?

Regards,

If your potential file only has parameters for N atoms, then you can create a Tersoff potential for N/C/H atoms because you don’t have the cross terms between N-C and N-H. So the answer is No, you can not do that.

Ray

In fact, there are parameters for C, N and H independently and we should provide the interaction between them by using these parameters. Which parameters or terms do we need to provide interactions? I think we have sufficient data but I don’t know how can I provide them all in one .Tersoff file.

Thanks,
Shahriar

In that case, you should study one of the Tersoff potential files for mixtures and the Tersoff paper for finding how to mix parameters using the mixing rules.

Ray

Do you know any sample files or any of such a kind of papers which describes these methods? If so, it would be my pleasure if you can let me know.

Shahriar

I thought I have said that already.

Ray

In fact, there are parameters for C, N and H independently and we should
provide the interaction between them by using these parameters. Which
parameters or terms do we need to provide interactions? I think we have
sufficient data but I don't know how can I provide them all in one .Tersoff
file.

​at the very least, try using google. then you might discover (when
searching for: tersoff mix parameters) , e.g. this URL

http://jespertoftkristensen.com/JTK/Blog/Entries/2013/12/14_Script_to_Output_any_Tersoff_Mixing_Parameters.html

which seems to be doing what you are looking for. the rest is your job
(especially the *validation* of the combined potential file), and not
really a LAMMPS problem.

axel.