Hello,
I got the following warning in my simulation where I used Aug/5/2013 version of LAMMPS. When I used Jan/11/2012 version LAMMPS, I didn’t get this error.
WARNING: Using a manybody potential with bonds/angles/dihedrals and special_bond exclusions
I used the following setting for potential:
pair_style hybrid lj/cut/coul/long 10.0 rebo
pair_coeff * * rebo CH.airebo C H C H NULL NULL
pair_coeff * * lj/cut/coul/long 0.0067 3.166 # O-O
bond_style harmonic
bond_coeff 1 2.1 1.5
angle_style harmonic
angle_coeff 1 1.829 109.47
kspace_style pppm 1.0e-5 #final npt relaxation
kspace_modify slab 3.0
Thanks,
Farshad
Hello,
I got the following warning in my simulation where I used Aug/5/2013 version
of LAMMPS. When I used Jan/11/2012 version LAMMPS, I didn't get this error.
WARNING: Using a manybody potential with bonds/angles/dihedrals and
special_bond exclusions
it is a *warning*, not an error, and you cannot see it with the older
code, since it wasn't programmed then.
it reminds you that you better know what you are doing, and that you
must not have any bonds defined for the parts of your system that you
represent with a manybody potential.
I used the following setting for potential:
pair_style hybrid lj/cut/coul/long 10.0 rebo
pair_coeff * * rebo CH.airebo C H C H NULL NULL
pair_coeff * * lj/cut/coul/long 0.0067 3.166 # O-O
this setup makes no sense at all. the second line will cancel the
first. how can this input work correctly?
axel.
Hello,
I got the following warning in my simulation where I used Aug/5/2013 version
of LAMMPS. When I used Jan/11/2012 version LAMMPS, I didn't get this error.
WARNING: Using a manybody potential with bonds/angles/dihedrals and
special_bond exclusions
it is a *warning*, not an error, and you cannot see it with the older
code, since it wasn't programmed then.
it reminds you that you better know what you are doing, and that you
must not have any bonds defined for the parts of your system that you
represent with a manybody potential.
I used the following setting for potential:
pair_style hybrid lj/cut/coul/long 10.0 rebo
pair_coeff * * rebo CH.airebo C H C H NULL NULL
pair_coeff * * lj/cut/coul/long 0.0067 3.166 # O-O
this setup makes no sense at all. the second line will cancel the
first. how can this input work correctly?
to be more accurate: the second "pair_coeff" statement cancels the first.
axel.
Thanks Alex for your response.
I just wanted to make sure if the accuracy of my results are reliable with this warning or not. Regarding the pair_coefficient, the following is the complete list of them:
pair_style hybrid/overlay lj/cut/coul/long 10.0 rebo
pair_coeff * * rebo CH.airebo C H C H NULL NULL
pair_coeff 1 5 lj/cut/coul/long 0.0 0.0
pair_coeff 1 6 lj/cut/coul/long 0.087 0.86
pair_coeff 2 5 lj/cut/coul/long 0.0 0.0
pair_coeff 2 6 lj/cut/coul/long 0.0036 1.7753
pair_coeff 3 5 lj/cut/coul/long 0.0 0.0
pair_coeff 3 6 lj/cut/coul/long 0.087 0.86
pair_coeff 4 5 lj/cut/coul/long 0.0 0.0
pair_coeff 4 6 lj/cut/coul/long 0.0036 1.7753
pair_coeff 5 5 lj/cut/coul/long 0.0 0.0
pair_coeff 5 6 lj/cut/coul/long 0.0 0.0
pair_coeff 6 6 lj/cut/coul/long 0.0067 3.166
bond_style harmonic
bond_coeff 1 2.1 1.5
bond_coeff 2 2.1 1.1
bond_coeff 3 7.669 1.0
angle_style harmonic
angle_coeff 1 1.829 109.47
kspace_style pppm 1.0e-5 #final npt relaxation
Thanks Alex for your response.
I just wanted to make sure if the accuracy of my results are reliable with
this warning or not. Regarding the pair_coefficient, the following is the
complete list of them:
this proves *again* the pointlessness of providing incomplete information.
it is impossible to make a statement about the correctness without
looking at the complete data and making some tests. nobody can say
with the (still very limited) information you provide here and nobody
will be running any tests for you, since this is an issue of your
simulation and not a problem of LAMMPS acting incorrectly. if you
don't know yourself whether your input is correct or now, you have to
find a way to figure it out. it doesn't get any more or less correct
if somebody here tells you to go ahead to that your input is wrong.
that is the way how research works. if we would know the answer
immediately and right away, you would not need to do research or learn
how to do it. 
axel.