How to write the Tersoff_ZRL form in GULP

GULP
1

Dear Julian and other users:

I am a beginner in the GULP software. Currently, I am using GULP to study the BeO system, whose interatomic potentials are in the Tersoff_ZRL form. However, I am not sure how to convert the parameters from the literature into a format recognized by GULP. The Example 57 given online, “Example of a Hessian calculation for Tersoff ZRL. Geometry is chosen so that the coordination term is non-zero,” only provides the library tersoff_zrl. Could you provide me with the form of the Tersoff ZRL potential in GULP, or give some references? Alternatively, could you advise me on how to convert the Tersoff ZRL potential from LAMMPS into GULP format? Thank you very much for your help.

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Dear Yongliang,
The functional forms are usually given in the help.txt (or web version) that comes with GULP. In the case of the “zrl” form of the bond order potentials, there is a reference given to:

Billeter et al (Phys. Rev. B, 73, 155329 (2006))

Hopefully this should give you the info you need.
Regards,
Julian

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Dear Julian，
Thank you for your reply. I still have one question: you mentioned that “The functional forms are usually given in the help.txt (or web version),” but I can’t seem to find them. Could you please provide a more specific path?
Thank you again for your help.
Best regards，
Yongliang

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There’s a file in the top level of the code called README which explains where things are, such as:
Docs : documentation and information relating to the program
You’ll find the manual and help in Docs, as per other codes.