Describe interlayer interaction using morse and LJ/cut

LAMMPS LAMMPS Beginners
1

Dear all,

I constructed a 2D materials model containing the elements of B, N, and C. I used a BNC tersoff potential to describe the in-plane interaction among B-N-C. But this potential shows a poor performance in describing interlayer interaction between the neighboring layers , such as BN layer and Carbon layers, and two BN layers.

So, to address this issue, I used a morse potential for a better modelling the weak interaction between BN and carbon layers. And also found a LJ parameter to deal with the interlayer interaction between two BN layers. (more detailed setting can be found below)

The simulation can be proceed correctly when only tersoff and morse potentials are used. But, once the LJ parameter that used to describe the layer interaction of BN. The simulation is stopped by a error of “Segmentation fault (core dumped)”.

------------- Initialization

units metal
dimension 2
atom_style atomic
boundary p p p
box tilt large

------------- System definition

read_data BN_Gra-27.6nm-3l-AP3-bulk4.data

------------- Simulation settings

pair_style hybrid/overlay tersoff morse 4 lj/cut 4
#pair_style hybrid/overlay tersoff lj/cut 4
pair_coeff * * tersoff BNC.tersoff B N C
pair_coeff 1 3 morse 0.0029 2.08 3.56
pair_coeff 2 3 morse 0.0083 2.54 3.54
pair_coeff 1 2 lj/cut 0.004 3.212
neigh_modify every 1 delay 10 check yes
write_dump all xyz opt.xyz modify element B N C
dump mydmp all atom 1000 dump.lammpstrj
region bulk block 0.0 276.115 0.0 239.1213922167 1.7 5.3
group bulk region bulk

------------- Run

thermo 5
#timestep 0.005
minimize 1.0e-5 1.0e-6 1000 10000
write_data BN_Gra-27.6nm-3l-AP3-bulk4-opt.data

------------- MD

fix 1 all nvt temp 50.0 50.0 5
#fix mynve all nve
#fix mylgv all langevin 300 300 0.1 10000
fix 3 bulk enforce2d
thermo 1000
run 500000
write_data BN_Gra-27.6nm-3l-AP3-bulk4-final.data
dump 1 all movie 1000 movie.avi type type
write_dump all xyz all.xyz modify element B N C

Can someone give me some guidance about how the error occurs and how to solve this issue?

Thanks in advance.

Guo

2

dimension 2 makes no sense for your system.

Also, please report your exact LAMMPS version.

Please note that LAMMPS ships with the INTERLAYER package containing pair styles specifically written for applications like yours.

4

Dear Akohlmey,

Thanks you for the guidance.

May I know why dimension 2 makes no sense for my system? Actually, I simulated a 2D material system like a surface with several layers.

It seems that I include all possible pairs. Why the computation is stopped only when LJ is added into the simulation?

5

Please read the documentation.
With dimension 2 all z-coordinates must be zero.
You have a 3-dim system that is just periodic in 2 dimensions.

6

Without knowing what LAMMPS version you use and having access to the files needed to run your input deck, it is difficult to make any specific statements.

Overall, your model is flawed, anyways. You are double counting interlayer interactions.
As mentioned before, you should consider using the available INTERLAYER potentials, which come with examples showing how to correctly set up your system and apply those based on the explanation in the documentation of those pair styles and the associated publications.

7

Dear Akohlmey,

Many thanks for detailed instruction. I will check it following your valuable suggestions!

Best regards,
Xiangyu