# Problem with hybrid pair style

Hi,

I am trying to find the migration energy of helium through an Fe lattice
through NEB. I am using a hybrid pair style, using a table style for the
interaction between helium and iron (pair style potential) and an eam
potential for Fe-Fe interactions (many bodied potential). I keep getting
the message "Pair coeff for hybrid has invalid style". I read on another
thread that many bodied potentials need the pair coeff as "pair_coeff *
* Fe_mm.eam.fs Fe Null" as oposed to "pair_coeff 1 1 Fe_mm.eam.fs". I
also read that you cannot have a self-self many body potential and a
mixed many body potential (but I believe I have a self-self many body
and a mixed pair potential).

Here is my the relevant part of my input file:

units metal

atom_style atomic
atom_modify map array
boundary p p p
atom_modify sort 0 0.0

# coordination number cutoff
variable r equal 2.835

# bcc unit cell
variable a equal 2.855324
lattice bcc \$a

region myreg block 0 4 &
0 4 &
0 4

create_box 2 myreg

create_atoms 1 region myreg
create_atoms 2 single 1.5 1.5 1.5

mass 1 55.845
mass 2 4.00

group Fe type 1
group He type 2

# make a vacancy
group del id 85 44
delete_atoms group del
group vacneigh id 46 52 54 76 78 84 86

# choose potential
pair_style hybrid eam/fs table linear 268
pair_coeff * * Fe_mm.eam.fs Fe Null
pair_coeff 1 2 DMOL.table DMOL_FE 286

Here's part of my input for the table potential:

# DMOL potential for Fe-He #(one or more comment or blank lines)
DMOL_FE #(keyword is first text on line)
N 268 #(N, R, RSQ, BITMAP, FPRIME parameters)
#(blank)
1 0.001 742308.990941 374379882.807
2 0.002 367929.108134 124782308.295
3 0.003 243146.799839 62357436.139
4 0.004 180789.3637 37403250.35
5 0.005 143386.11335 24923545.156
6 0.006 118462.568194 17789142.938
7 0.007 100673.425256 13328657.112
8 0.008 87344.768144 10354494.221
9 0.009 76990.273923 8270528.493
10 0.01 68719.74543 6755756.963
11 0.011 61963.988467 5619622.116
12 0.012 56344.366351 4746411.52
13 0.013 51597.954831 4061467.748
14 0.014 47536.487083 3513607.57
15 0.015 44022.879513 3068257.259
...

If anyone can shed some light on where I am going wrong, I would be most
grateful.

Regards

Luke

pair_style hybrid eam/fs table linear 268
pair_coeff * * Fe_mm.eam.fs Fe Null
pair_coeff 1 2 DMOL.table DMOL_FE 286

The pair coeff commands need the name of which style

added. E.g. * * eam/fs, and 1 2 table …

See the pair_style hybrid doc page for details.

Steve