Dear LAMMPS users,
I am trying to simulate water inside a graphene sheet reservoir to make thermally-driven flow into CNT. I have 9 different atom types which 1 is Hydrogen and 2 is Oxygene and the rest of them are carbon. You can find the geometry in the attached file. I defined pair style_hybrid as below but I got an error where Tersoff potential is introduced.
I highly appreciate your time and help.
pair_style hybrid lj/charmm/coul/long 8.0 10.0 lj/cut 10.0 tersoff
pair_coeff * * lj/cut 0 0
pair_coeff 1 1 lj/charmm/coul/long 0.001995 0.4000
pair_coeff 2 2 lj/charmm/coul/long 0.00659 3.1507
pair_coeff 1 2 lj/charmm/coul/long 0.003625 1.77535
pair_coeff 1 3 lj/charmm/coul/long 0 0
pair_coeff 2 3 lj/charmm/coul/long 0.0040632 3.19
pair_coeff 1 4 lj/charmm/coul/long 0 0
pair_coeff 2 4 lj/charmm/coul/long 0.0040632 3.19
pair_coeff 1 5 lj/charmm/coul/long 0 0
pair_coeff 2 5 lj/charmm/coul/long 0.0040632 3.19
pair_coeff 1 6 lj/charmm/coul/long 0 0
pair_coeff 2 6 lj/charmm/coul/long 0.0040632 3.19
pair_coeff 1 7 lj/charmm/coul/long 0 0
pair_coeff 2 7 lj/charmm/coul/long 0.0040632 3.19
pair_coeff 1 8 lj/charmm/coul/long 0 0
pair_coeff 2 8 lj/charmm/coul/long 0.0040632 3.19
pair_coeff 1 9 lj/charmm/coul/long 0 0
pair_coeff 2 9 lj/charmm/coul/long 0.0040632 3.19
pair_coeff 3* 3* SiC.tersoff C C
problem.pptx (117 KB)
Dear LAMMPS users,
I am trying to simulate water inside a graphene sheet reservoir to make thermally-driven flow into CNT. I have 9 different atom types which 1 is Hydrogen and 2 is Oxygene and the rest of them are carbon. You can find the geometry in the attached file. I defined pair style_hybrid as below but I got an error where Tersoff potential is introduced.
you get an error, because the syntax is incorrect. please carefully re-read the documentation for pair_style, pair_coeff, pair_style tersoff and pair_style hybrid. manybody potentials like tersoff, need a particular way to enter pair_coeff commands.
some more general comments:
- your use of lj/cut is pointless and potentially problematic: it will be wiped out, if all pair_coeffs are entered correctly, and if some required pair_coeff entries are missing, it will hide that fact, and you are potentially running with bogus force field settings.
- your carbon atoms are not likely to have partial charges, so using a pair (sub-)style including coulomb interactions is wasteful
- if there are no interactions to be computed, it is more efficient to use either pair (sub-)style none or zero
- you incorrectly use a type range for tersoff, but do not use it for your lj/charmm/coul/long terms, where it is correct to use and would massively simplify your input.
axel.
Dear Lammps users,
I have 9 different types of atoms in my simulation. 1st and 2nd are Hydrogen and Oxygen related to water molecules and the rest of them are Carbon atoms. I used pair_style hybrid to define the potentials between atoms. The potentials are defined as below and the error is in the following.
pair_style hybrid lj/charmm/coul/long 8.0 10.0 lj/cut 12
pair_coeff * * SiC.tersoff NULL NULL C C C C C C C
pair_coeff 1 1 lj/charmm/coul/long 0.001995 0.4000
pair_coeff 2 2 lj/charmm/coul/long 0.00659 3.1507
pair_coeff 1 2 lj/charmm/coul/long 0.003625 1.77535
pair_coeff 1 3* none
pair_coeff 2 3* lj/cut 0.0040632 3.19
ERROR: Pair coeff for hybrid has invalid style (…/pair_hybrid.cpp:414)
Last command: pair_coeff * * SiC.tersoff NULL NULL NULL C C C C C C
Thanks,
Dear Lammps users,
I have 9 different types of atoms in my simulation. 1st and 2nd are Hydrogen and Oxygen related to water molecules and the rest of them are Carbon atoms. I used pair_style hybrid to define the potentials between atoms. The potentials are defined as below and the error is in the following.
pair_style hybrid lj/charmm/coul/long 8.0 10.0 lj/cut 12
pair_coeff * * SiC.tersoff NULL NULL C C C C C C C
pair_coeff 1 1 lj/charmm/coul/long 0.001995 0.4000
pair_coeff 2 2 lj/charmm/coul/long 0.00659 3.1507
pair_coeff 1 2 lj/charmm/coul/long 0.003625 1.77535
pair_coeff 1 3* none
pair_coeff 2 3* lj/cut 0.0040632 3.19
ERROR: Pair coeff for hybrid has invalid style (…/pair_hybrid.cpp:414)
Last command: pair_coeff * * SiC.tersoff NULL NULL NULL C C C C C C
http://lammps.sandia.gov/doc/Section_errors.html