Can anyone suggest me how to make a proper potential file for LAMMPS molecular dynamics simulation for Boron Nitride? (BN).
The easiest route you can take is to find some proper paper that already simulated the Boron Nitride with the use of MD and try to reflect the parameters they used, i.e.
- form of the potential
- initial geometry for such lattice
- probably some other things if necessary
Then you are able to validate your results right away at the same conditions as these authors reported and if it all works fine, then you’re ready to delve into your project of interest.
PS. There’s a project called OpenKim which has a tremendous database for different interparticle potentials.
The file format of the potential files for different pair styles is described in the respective pair style documentation. You can then take the parameters from a publication and build a potential file for them.
Sometimes, that requires converting units or computing some derived properties and in the extreme case, even creating some spline tables.
But before doing that, you can consider using potential files bundled with LAMMPS (there are two that are compatible with BN in the potentials folder of the LAMMPS distribution) and there are multiple data bases with potential files specifically focused on manybody potentials that will cover BN materials.
Please always make certain that you validate any potential files, be them provided by others or be it that you created them yourselves.
Hello! Thanks for the answer.
I tried out some papers…also the documentation file. Is there any specific way how I can modify the potential parameters ?? Also the format which I got from papers don’t exactly match with format given inside potential of Lammps folder.
What do you mean by “modifying potential parameters”?
If you would like to change a parameter manually you open the respective file and edit it, but why would you want to change a force-field which has already been generated for your material? Changing FF parameters is a fairly sensitive thing and doing modifications that might make sense is far more tedious than one may imagine.
I am also unsure about “format”. Do you mean form of an interatomic potential e.g. Lennard-Jones? There are multiple ways of writing it, but one can easily convert between respective forms (Lennard-Jones potential - Wikipedia).
If, by format you mean a correctly written file including topology and interactions, this is something you will likely have to do by yourself. For instance, a simple Python script would be capable of handling that.
I have been trying to modify a tersoff potential e.g SiC.tersoff file from Lammps potential folder. Suppose i want to introduce doping in the crystal,then I have to modify the potential right?
I am asking help for that.
Not necessarily. What kind of doping of what kind of system do you want to do?
You cannot get (much) help, if you ask confusing or vague questions and do not provide any context and specific examples with specific problems.