How can I use Si.tersoff.modс potential?

Hello,
I want to use Si.tersoff.modс but I cannot get any information about this potential. Is it potential file? And how it can be applied to LAMMPS.
If I use this file lammps show me an error: “Incorrect format in Tersoff potential file (…/pair_tersoff_mod.cpp:114)”
LAMMPS version - 8Mar18-MPI

Script:

package omp 16
units metal
lattice diamond 5.43

region box block 0 10 0 10 0 10
region box1 block -5 9.999999 0 10 0 10
region box2 block 10 25 0 10 0 10

create_box 1 box
create_atoms 1 box
group gr1 dynamic all region box1 every 100
group gr2 dynamic all region box2 every 100
mass 1 28.0
velocity all create 600 2785387
timestep 0.002

pair_style tersoff/mod
pair_coeff * * …/lammps/potentials/Si.tersoff.modc Si

neighbor 0.5 bin
neigh_modify every 5 delay 0 check yes

variable t0 equal temp+400*dt

fix 123 all temp/berendsen v_t0 5000.0 0.5
fix 1 all nve

compute cc1 all chunk/atom bin/1d x lower 8 units box
compute vbias all temp/profile 1 1 1 x 10
compute peratom all stress/atom NULL

variable pr atom -(c_peratom[1]+c_peratom[2]+c_peratom[3])/3/vol*8000

variable ent atom enthalpy

fix 2 all ave/chunk 1 1000 10000 cc1 temp density/mass vx v_pr v_ent bias vbias file tmpswlx.out
fix 3 all press/berendsen iso 0e0 0e0 4000.0

thermo_style custom step temp etotal density press lx
thermo_modify lost ignore
thermo 1000

dump id all custom 10000 dumpswlx.si x y z vx vy vz
restart 20000 si_restartswlx
run 8000000

Thanks in advance.

Hello,
I want to use Si.tersoff.modс but I cannot get any information about this
potential. Is it potential file? And how it can be applied to LAMMPS.

you need to use pair style tersoff/mod/c not tersoff/mod.

axel.

I don’t recall why/how this file is included in the LAMMPS potentials dir. The

header is not very descriptitve. It is also named with an incorrect suffix (modc).

I’m CCing Aidan to see if he recalls where this came from. Or you can email

the author in the header file, if you can find him.

Steve

oops - Axel is right. I searched for modc, not mod_c in the src

files and didn’t see it. That’s why the suffix is modc. It has a slightly

different format.

Steve