sputtring the Si on substrate C diamond

Hi dears lamps§users. I do the program below,but i received this message ‘’ ERROR: Invalid pair style (force.cpp:168)’'who is the wrong please?.
my greetings.

Energy : eV Distance : Angstrom Mass :Kg Time : picosec

units metal
#Classical particles
atom_style atomic
#p=Periodic , f=fixed
boundary p p f
#lattice constant i.e. C-diamond 4.05
variable a equal 4.05

diamond structure

lattice diamond $a

Specify simulation box

region box block 0 10 0 10 0 10

Initiate box with 1 atom type

create_box 1 box
mass 1 12.0

Inter atomic potential - Tersoff 1989

pair_style Tersoff

interaction pairs ,file name,Element parameters

pair_coeff * * SiC.tersoff Si C Si
region fixlayer block 0.0 40.50 0.0 40.50 0 3.0 units box
region thermolayer block 0.0 40.50 0.0 40.50 3.0 25.05 units box
region sputter block 0.0 40.50 0.0 40.50 25.05 40.50 units box
region model block 0.0 40.50 0.0 40.50 0.0 40.5 units box

Create 1 atom type on lattice in simulation box

create_atoms 1 box
#Specify build neighbor list ,use cutoff+0.3A
neighbor 0.3 bin
#Frequency to re build neighborlist
neigh_modify every 20 delay 0 check no
#Compute the energy per atom
compute eperat all pe/atom
#Output x , y , z of atoms LAMMPS standard format
dump config all atom 10 dump.Cdiamond_{a} #Custom output of atom properties dump config all custom 10 dump . Cdiamond_{a} &
id type x y z c_eperat
timestep 0.001
#Basic setup sputtering of carbon on Silicon .
fix 4 all deposit 500 2 500 95485 region sput near 1.2 &
vz -0.5 -1.5 target 12.0 12.0 28.0 units box
#Ensemble
fix 1 all nve
#Frequency of Ensemble data output to screen
thermo 500
#Data that is output to screen
thermo_style custom step pe ke temp vol press
run 10000

Hi dears lamps§users. I do the program below,but i received this message ''
ERROR: Invalid pair style (force.cpp:168)''who is the wrong please?.

http://lammps.sandia.gov/doc/Section_errors.html