Pair_style hybrid with SW and Tersoff Potential

Dear LAMMPS users,

I am trying to insert a new group of atoms into an existing simulation box by deleting atoms that initially occupied the position in which the new group would be located. I intend to introduce a hybrid potential such that the existing atoms are SW si and the new atoms would be modeled by TERSOFF si potential and the interaction between the 2 different si groups will be modeled by Ziegler.

units metal
dimension 3
boundary p p p
atom_style atomic
newton on

lattice diamond 5.4307 orient x 1 0 -1 orient y -1 2 -1 orient z 1 1 1
neighbor 2.0 bin
neigh_modify every 1 delay 0 check yes


region solid block INF INF INF INF 0 8 units lattice
region cleave1 block INF INF INF INF 3.828 4.215 units lattice

group sol region solid
group wall region cleave1

pair_style hybrid sw tersoff ziegler 2.0
pair_coeff * * sw si.sw Si NULL
pair_coeff * * tersoff Si.tersoff NULL Si
pair_coeff 1 2 ziegler 14 14 3.0

mass 1 28.0855
mass 2 28.0855

delete_atoms group wall
create_atoms 2 region cleave1

compute x all property/atom x
compute k all ke/atom
compute p all pe/atom
compute cc all chunk/atom bin/1d z lower 1 units lattice
variable kb equal 8.617339e-5
variable temp atom c_k/(1.5*v_kb)
variable atomEng atom c_k+c_p

dump id all custom 1000 step_1.d id x y z c_k c_p v_temp v_atomEng type vx vy vz
log step_1.log
thermo_style custom step temp press ke pe density enthalpy lx ly lz
thermo 1000

restart 20000 restart_step1_1 restart_step1_2

minimize 1.0e-4 1.0e-6 100 1000

fix 1 all nvt temp 1685 1685 1
run 100000
unfix 1
undump id

I ran the input file above on 06 Jan 2017 LAMMPS version and got the error message "ERROR: Illegal pair_style command (…/pair_tersoff.cpp:285)’'

Please, I would appreciate suggestions from you all on how to go about setting up my simulation.


There is no pair style “ziegler” in LAMMPS.
If the pair style is not recognized, the keywords are assumed to be arguments to the previous substyle, hence the error from the tersoff style.