Error with pair style hybrid

Dear Lammps users,

I am trying to use a pair_style Hybrid. Individual styles run OK. but does not run for the mixed structure.

I have 4 atom types : 1 & 2 are by eam/alloy, 3 is eam and 4 is by airebo
I made the script like this :
pair_style hybrid eam/alloy eam lj/cut 8.0 lj/cut 10.0 airebo 3.0 1 1
pair_coeff * * eam/alloy …/lammps-31Jul12/potentials/CoAl.eam.alloy Co Al NULL NULL
pair_coeff 3 3 eam …/lammps-31Jul12/potentials/Au_u3.eam
pair_coeff * * airebo …/lammps-31Jul12/potentials/CH.airebo NULL NULL NULL C
pair_coeff *2 3 lj/cut 0.5 1.3
pair_coeff 3 4 lj/cut 0.5 1.5

Why I get error "pair coefficient for hybrid has invalis style "

Thank you very much for suggestions.

Regards
Mousumi

pair_style hybrid eam/alloy eam lj/cut 8.0 lj/cut 10.0 airebo 3.0 1 1
pair_coeff *2 3 lj/cut 0.5 1.3

The 2nd line needs to be
pair_coeff *2 3 lj/cut N 0.5 1.3

where N = 1 or 2, b/c you have listed lj/cut twice in the
pair style command.

See the pair_style hybrid doc page for details.

Steve

Hello Steve,
Thanks for the reply, I did the modification, but it still gives the same error: " incorrect arg for pair coefficient hybrid",
I understand that if I make *2 then it inlcudes both 1 & 2, so why I need to put N and specify as ‘where N = 1 or 2’
However there is something not right in the way I specified the pair_style, cannot see what it is.

pair_style hybrid eam/alloy eam lj/cut 8.0 lj/cut 10.0 airebo 3.0 1 1
pair_coeff * * eam/alloy …/lammps-31Jul12/potentials/CoAl.eam.alloy Co Al NULL NULL
pair_coeff 3 3 eam …/lammps-31Jul12/potentials/Au_u3.eam
pair_coeff * * airebo …/lammps-31Jul12/potentials/CH.airebo NULL NULL NULL C
pair_coeff *2 3 lj/cut N 0.5 1.3
where N = 1 or 2
pair_coeff 3 4 lj/cut 0.5 1.5

Also when I include H in my model ( I tried a C H only system with ~10%H using airebo) the energy becomes ‘nan’. It works only when I delete H. Why is this ?
This is how I put :

pair_style airebo 3.0 1 1
pair_coeff * * …/lammps-31Jul12/potentials/CH.airebo C H

Thanks for your help,
Regards
Mousumi

Hello Steve,
Thanks for the reply, I did the modification, but it still gives the same
error: " incorrect arg for pair coefficient hybrid",
I understand that if I make *2 then it inlcudes both 1 & 2, so why I need to
put N and specify as 'where N = 1 or 2'
However there is something not right in the way I specified the pair_style,
cannot see what it is.

your main problems doesn't seem to be with LAMMPS, but with the grey
stuff to the left of your right ear.

of course, you were not to put in the text literally. this would be
stupid. i also don't get why you have to specify lj/cut twice, since
you can specify the cutoff just as well with the pair coefficients.
re-read the documentation of the hybrid pair style and all other pair
styles again and then build your input in small steps so you can see
where and how it fails. if you do it right, it will work. in fact, it
is fairly trivial to get it right.

axel.