Dear All:
In the lammps manual,I read :The values of Z_i and Z_j are normally equal to the atomic numbers of the two atom types. Thus, the user may optionally specify only the coefficients for each I==I pair, and rely on the obvious mixing rule for cross interactions. I do not understand.
If i want to use zbl potential for atom type 1 and atom type 2. then how can i write my commands?
Or i can write pair_style zbl 3.0 4.0
then next how do i set coeffients for 1-2 interactions with zbl potential.Thanks very much.
Dear All:
In the lammps manual,I read :The values of Z_i and Z_j are normally equal
to the atomic numbers of the two atom types. Thus, the user may optionally
specify only the coefficients for each I==I pair, and rely on the obvious
mixing rule for cross interactions. I do not understand.
if your atom type 1 has the atomic number 12 and your atom type 2 has the
atomic number 14, what are the Z_i, Z_j parameters for atom type 1
interacting with atom type 1, atom type 2 interacting with atom type 2 and
finally atom type 1 interacting with atom type 2?
If i want to use zbl potential for atom type 1 and atom type 2. then how
can i write my commands?
Or i can write pair_style zbl 3.0 4.0
your question above is in reference to the necessary pair_coeff
statements, not pair_style. the parameters following the pair style
command are the cutoffs for the switching function.
then next how do i set coeffients for 1-2 interactions with zbl
potential.Thanks very much.
the documentation explains this very clearly. please re-read it carefully
keeping the hints in this e-mail in mind. if this still confuses you, i
suggest you go back to the beginning of the documentation and study some
simple examples, e.g. using Lennard-Jones potentials before trying this
case.
axel.
I am doing the work about ion bombardment of Silicon substrate.And I set silicon atoms as atom type 1,set gallium ion as atom type 2.So i use tersoff/zbl potential for si-si interactions,and use zbl potential for Si-Ga and Ga-Ga interactions.
I have installed the lammps in my personnal computer,which the lammps version is 28 March20 2016.And my commands are pair_style hybrid tersoff/zbl zbl 3.0 4.0
pair_coeff * * tersoff/zbl SiC.tersoff.zbl Si NULL
pair_coeff 1 2 zbl 14 31
pair_coeff 2 2 zbl 31 31
And the commands above run well.And after running my input script ,I get the right results.
When I run my input script in Supercomputing Center.The lammps version there is 15 May 2015. But when I run the same script ,I get the error:incorrect args for pair_coeffients(pair_zbl.cpp 207).So I am confused.
Then I read a lot to find out the problem.Some say that maybe it is a bug in low version .The manual tell me that I can use mixing rule to set the coeffients for 1-2 interactions.I really do not know how to solve this problem in low version of lammps.
So when I run my input script in Supercomputing Center,I do not know how to write my conmmands.
Best regards.
I am doing the work about ion bombardment of Silicon substrate.And I set
silicon atoms as atom type 1,set gallium ion as atom type 2.So i use
tersoff/zbl potential for si-si interactions,and use zbl potential for
Si-Ga and Ga-Ga interactions.
I have installed the lammps in my personnal computer,which the lammps
version is 28 March20 2016.And my commands are pair_style hybrid
tersoff/zbl zbl 3.0 4.0
pair_coeff * * tersoff/zbl SiC.tersoff.zbl Si NULL
pair_coeff 1 2 zbl 14 31
pair_coeff 2 2 zbl 31 31
And the commands above run well.And after running my input script ,I get
the right results.
When I run my input script in Supercomputing Center.The lammps version
there is 15 May 2015. But when I run the same script ,I get the
error:incorrect args for pair_coeffients(pair_zbl.cpp 207).So I am confused.
this is a *very* different question than what you originally posted.
Then I read a lot to find out the problem.Some say that maybe it is a bug
in low version .The manual tell me that I can use mixing rule to set the
coeffients for 1-2 interactions.I really do not know how to solve this
problem in low version of lammps.
So when I run my input script in Supercomputing Center,I do not know how
to write my conmmands.
as stated on the LAMMPS homepage and in the LAMMPS documentation, the
LAMMPS software package is continuously updated and thus the online manual
always represents only the latest (development) version. thus to find out
how to write correct input for an older version of LAMMPS, you have to
study the corresponding documentation for that older version. in case of
the zbl potential, you should find that with the 15 May 2015 version it is
not possible to do the calculation, that you are doing due to a limitation
of the zbl potential implementation. this limitation was lifted in the 24
Sep 2015 patch, as shown in the bugfix and new features change log at:
http://lammps.sandia.gov/bug2015.html
the logical conclusions is, that you need to upgrade the LAMMPS version on
that remote machine to a recent version of LAMMPS and it will work. since
compiling LAMMPS doesn't require any special privileges, there should be no
problem with that.
axel.
Thank you very much.I am very sorry for not telling the detailed yesterday .I will try to install the new version on Supercomputing Center.