Dear LAMMPS users,
I am tying to model 2 types of atoms, Graphene sheet over silicon, according to literature, I am using Sterling-Weber potential for Silicon, AIREBO for Graphene sheet and lj/cut for Si-C. I use these lines for pair styles, but go this error message: " ERROR: Pair coeff for hybrid has invalid style (…/pair_hybrid.cpp:353)".
pair_style hybrid lj/cut 2.5 airebo 3.0 sw
pair_coeff 1 2 lj/cut 1.0 1.5
pair_coeff 2 2 ./CH.airebo C
pair_coeff 1 1 sw Si.sw Si
I appreciate your time and helps.
Best Regards,
Ali
Dear LAMMPS users,
I am tying to model 2 types of atoms, Graphene sheet over silicon, according
to literature, I am using Sterling-Weber potential for Silicon, AIREBO for
Graphene sheet and lj/cut for Si-C. I use these lines for pair styles, but
go this error message: " ERROR: Pair coeff for hybrid has invalid style
(../pair_hybrid.cpp:353)".
if you run your input with the -echo screen flag, you can see which
line(s) are the offending ones and then you should consult the
documentation of the respective pair style as well as the hybrid pair
style documentation to compare if your input is consistent with what
the documentation requires.
axel.
Dear Axel,
Thank you for your response, I always do so for test runs. I have used both the AIREBO and SW potentials for single silicon and single graphene systems before. the code encounters error in this line:
“pair_coeff 2 2 ./CH.airebo C”
according to the documentation I should define the sub-styles by their usual arguments. I use the AIREBO potential with the same exact line, in single graphene run. (just I put * * instead of 2 2).
Thank you for your time and help.
Best Regards,
Ali
Dear Axel,
Thank you for your response, I always do so for test runs. I have used both
the AIREBO and SW potentials for single silicon and single graphene systems
before. the code encounters error in this line:
"pair_coeff 2 2 ./CH.airebo C"
according to the documentation I should define the sub-styles by their usual
arguments. I use the AIREBO potential with the same exact line, in single
graphene run. (just I put * * instead of 2 2).
were the carbon atoms in that input also mapped to type 2?? i doubt it.
please re-read the docs that i pointed out very carefully, and you'll
find your mistake.
axel.
yes, when I use the following lines in the hybrid command, I works, but the results are not good. The only problem is in these tree lines:
pair_style hybrid lj/cut 2.5 tersoff tersoff
pair_coeff * * tersoff 1 Si.tersoff Si NULL
pair_coeff * * tersoff 2 C.tersoff NULL C
pair_coeff 1 2 lj/cut 1.0 1.5
Best,
Ali
yes, when I use the following lines in the hybrid command, I works, but the
results are not good. The only problem is in these tree lines:
what does "the results are not good" mean?
how did you pick the parameters for lj/cut? neither cutoff, nor
epsilon or sigma look like they make sense for metal units (which are
required by tersoff, did you consider this?).
axel.
I just picked them from the documentation example to check that if my entire input file is correct or not. (it was in very early steps of the input file generation). I was not going to use the lj/cut potential for my simulation. I just wanted to check the hybrid pair style in my input. When I started to work on the pair style part, I encountered this error. I know the parameters do not make sense and when I run the simulation the materials act like liquids. It was just a test to make sure other parts of the input script has no errors.
Best,
Ali
I just picked them from the documentation example to check that if my entire
input file is correct or not. (it was in very early steps of the input file
generation). I was not going to use the lj/cut potential for my simulation.
I just wanted to check the hybrid pair style in my input. When I started to
work on the pair style part, I encountered this error. I know the parameters
do not make sense and when I run the simulation the materials act like
liquids. It was just a test to make sure other parts of the input script has
no errors.
well, LAMMPS will only detect errors in the syntax. if you make other
(semantic) mistakes (e.g. wrong units, wrong time step, wrong initial
structure, and so on) you may still get meaningless and unphysical
results. i doubt that the LJ parameters will result in your silicon
and carbon melting, so there are likely other problems.
axel.
Sure, thank you for your help. I just needed to solve the syntax error for the SW and AIREBO potentials.
Best,
Ali