eam and beck

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1

Dear LAMMPS users,

Is it possible to use EAM potential and beck together as hybrid potentials? I have 2 different atoms, One is a metal atom and another is Helium for which I want to use Beck
I am using the command

pair_style hybrid eam beck 8.0
pair_coeff * * eam nimib
pair_coeff 2 2 399.671876712 0.0000867636112694 0.675 4.390 0.0003746 6.0

I am getting the ERROR: Illegal pair_style command (…/pair_beck.cpp:175)

2

Dear LAMMPS users,

Is it possible to use EAM potential and beck together as hybrid potentials?

yes.

I have 2 different atoms, One is a metal atom and another is Helium for
which I want to use Beck

and what do you want to use to describe the interaction *between* the
metal and helium?

I am using the command

pair_style hybrid eam beck 8.0
pair_coeff * * eam nimib
pair_coeff 2 2 399.671876712 0.0000867636112694 0.675 4.390 0.0003746
6.0

I am getting the ERROR: Illegal pair_style command (../pair_beck.cpp:175)

it works for me. so did you cut-n-paste the "beck 8.0" from the manual?
then please check if you have proper valid 7-bit ASCII characters.
many web browsers these days replace regular space characters for
8-bit characters that have a different width.

or try deleting the line and typing it by hand.

axel.

3

Dear Axel,

Thank You for your reply.
I am using EAM interaction for metal atom and beck for helium in order to obtain interaction between metal and helium
After typing the beck 8.0 . Now I am getting the error as
ERROR on proc 0: All pair coeffs are not set (…/pair_hybrid.cpp:505) by using

pair_style hybrid eam beck 8.0

pair_coeff * * eam nimib
pair_coeff 2 2 beck 399.67 0.000086736 0.675 4.390 0.0003746 6.0

4

Dear Axel,

Thank You for your reply.
I am using EAM interaction for metal atom and beck for helium in order to
obtain interaction between metal and helium

no, you don't. you use EAM to get the interaction between the metal
atoms, and beck to model the interaction between helium atoms, but you
have nothing that computed the mixed interaction. how would have be
done. those are two very different models and neither of which knows
of the other.

After typing the beck 8.0 . Now I am getting the error as
ERROR on proc 0: All pair coeffs are not set (../pair_hybrid.cpp:505) by
using

pair_style hybrid eam beck 8.0
pair_coeff * * eam nimib
pair_coeff 2 2 beck 399.67 0.000086736 0.675 4.390 0.0003746 6.0

yes. and it is a well deserved order. your model is incomplete and
that is why i was asking. this "mixed" interaction is something that
*you* have to provide. this is not something that LAMMPS can do for
you.

axel.