Pair_style ilp/graphene/hbn

… and I think there rather is a problem with how you are creating your geometries and data files.

As you see, everybody can easily make unsubstantiated claims, but there is a crucial component missing here: reproduciblility. You are making a lot of speculations but have no proof. That is very unscientific (just like my speculation that your initial geometry is bogus). Now, I have proof that the pair style is functioning as documented by pointing you to the example and confirming that it can complete without failure (I just reran it).

Now the burden of proof is on you to properly argue your case and provide convincing proof that the pair style is broken. Statements like “my input keeps producing the same error, no matter what I do” is not it unless you can provide the info and data (i.e. inputs) where others can check it. Please see the suggestions about what to do so that people will be more likely to look into your issues in the forum guidelines: Please Read This First: Guidelines and Suggestions for posting LAMMPS questions