ZBL-hybrid overlay

Hi,

I’ve been trying to add a zbl correction to a ZrH potential using the pair style hybrid overlay.
I plotted the original eam potential and found where the zbl repulsion should start and using the previous example of the zbl tersoff potential, I’ve been trying to add the right pair_coefficient command so that between the Zr-H and Zr-Zr there is a zbl cutoff.

i’ve used the code :

pair_style hybrid/overlay eam/fs zbl 0.001 3.6

pair_coeff * * eam/fs ZrH_V4.fs Zr H

pair_coeff * * zbl 0.0
pair_coeff 1 1 zbl 2.3 3.6
pair_coeff 1 2 zbl 1.0 3.0

but I get the error

ERROR: Illegal pair_style command (…/pair_eam.cpp:338)

Could you advise how I can get this work please?

Thank you in advance

Hi,

I've been trying to add a zbl correction to a ZrH potential using the pair
style hybrid overlay.
I plotted the original eam potential and found where the zbl repulsion
should start and using the previous example of the zbl tersoff potential,
I've been trying to add the right pair_coefficient command so that between
the Zr-H and Zr-Zr there is a zbl cutoff.

i've used the code :

pair_style hybrid/overlay eam/fs zbl 0.001 3.6

pair_coeff * * eam/fs ZrH_V4.fs Zr H

pair_coeff * * zbl 0.0
pair_coeff 1 1 zbl 2.3 3.6
pair_coeff 1 2 zbl 1.0 3.0

but I get the error

ERROR: Illegal pair_style command (../pair_eam.cpp:338)

Could you advise how I can get this work please?

which version of LAMMPS are you using?

the pair_style command, that you quote here, works for me with the
current version of LAMMPS (18 Jun 2016).

please make certain, that your input contains only ASCII characters.
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sometimes replace regular space characters by non-ASCII versions with
a different width.

axel.

I'm using the 2014 version of lammps. I can get it to run on this version if I just use the pair_coeff * * zbl 0.0 command but not when I include the other pair interactions.
Was this changed for the newest version of lammps?

Thanks in advance

I'm using the 2014 version of lammps. I can get it to run on this version if I just use the pair_coeff * * zbl 0.0 command but not when I include the other pair interactions.

"2014 version" is rather vague, there are usually over a hundred
patchlevel releases of LAMMPS each year.

Was this changed for the newest version of lammps?

your problem is with the pair_style command, not pair_coeff.
i don't recall in detail all changes over the last couple of years.
all i can say is, that your pair_style command works with the current
version of LAMMPS.

axel.

Previously, the mixing rule was on the user's responsibility. In your
case, you would have to provide one atomic number only for such command,
and not two as in your example below:
pair_coeff 1 1 zbl 2.3 3.6
but a correct example (just an example, the value might be wrong!!!)
pair_coeff 1 1 zbl 2.9

But why not using one of the last stable version of Lammps?