Dear LAMMPS users,

I am trying to use the newly implemented Lebedeva interlayer potential to model two graphene layers (atomic types 1 and 2) with nitrogen defects (atomic type 3) in one of the layers. To do so, I considered C-N interlayer interactions equal to C-C, duplicating this entry in the potential file:

C C 14.558 21.204 1.8 3.198 4.16 -0.862 0.10049 0.6 0.4 1.0

C N 14.558 21.204 1.8 3.198 4.16 -0.862 0.10049 0.6 0.4 1.0

In my first attempt, I used the following commands to define the pair coefficients:

pair_style hybrid/overlay tersoff lebedeva/z 14

pair_coeff * * tersoff BNC.tersoff C C N

pair_coeff 1 2 lebedeva/z CN.Lebedeva C C

pair_coeff 2 3 lebedeva/z CN.Lebedeva C N

By running LAMMPS, I got the following error:

ERROR: Incorrect args for pair coefficients (…/pair_lebedeva_z.cpp:222)

Looking at the source file, I found at line 222:

if (narg != 3 + atom->ntypes)

error->all(FLERR,“Incorrect args for pair coefficients”);

Then I changed the input file:

pair_style hybrid/overlay tersoff lebedeva/z 14

pair_coeff * * tersoff BNC.tersoff C C N

pair_coeff 1 2*3 lebedeva/z CN.Lebedeva C C N

Now, when I run LAMMPS, the error is:

ERROR: Potential file is missing an entry (…/pair_lebedeva_z.cpp:431)

My simple question is: can I use Lebedeva’s potential to do this kind of simulation? If so, what am I doing wrong? The current documentation does not clarify the correct usage of this interatomic potential.

Thanks in advance,

Roberto