Dear authors and LAMMPS users,
dear polina,
I do the simulations of carbon nanotube with the REBO potential, I write
code based on a Brenner's Fortran code, I have found some strange behavior
of my system, using this code. I want to test my tasks using LAMMPS, I saw
that it have nice REBO potential with additions. However, It was dificult to
understand from the homepage how to build the input files.
the lammps distribution ships with many examples. the best way
to learn writing input files is to pick one that is close what
you need and adapt it. it usually also helps to first learn building
inputs from scratch with a trivial input example before moving
to your production system. every code has some quirks and idiosyncrasies
that one needs to understand first.
In my current code I have 2 input files:
1. coord.d XYZ coordinates of each atom (carbon atom in my case)
2. input.d The input file with the MD parameters.
And I have outputs with xyz coordinates of each carbon atom every N steps
and one more file with the energies and temperature also every N steps.
please note, that lammps is much more general and flexible compared to
the code that you are currently using. the drawback is that it is not
always that obvious what to do, but i am certain that once you get the
hang of it, you'll be missing the equivalent features in the other code.
Questions:
1. Can I use something like coord.d file as input for carbon nanotube
geometry?
the lammps equivalent would be the 'data' file. the format
is discussed in detail in the online documentation.
2. How many input files are required by LAMMPS?
depends. using one data or restart file and one
input script is typical. for more complicated scenarios
one may want to write the input script in fragments and
use the include statement to build the final script.
3. How can I define some atoms not to move?
please see the "fix setforce" command, also you
can just exclude them from the integrator.
4. Can you please send me any basic examples of input files for Carbon
nanotube?
there are plenty examples bundled with lammps that can
be easily adapted.
cheers,
axel.