[lammps-users] defining a cone of atoms

Dear Dr. Steve J Plimpton
Happy New Year. I am a doctoral student from Mechanical engineering
from Howard University, D.C mailing you. I am working on molecular dynamic
simulation of nano mechanical switches at a high frequency. I would like to
create a model in shape of a cone. But in the manual I find “region” comman=
that has box, cylinder and sphere options. If I should assemble the atoms i=
the shape of a cone what should I do? Is it possible in LAMMPS.

I would highly appreciate if you guide me on the above aspect or if you can
guide me in the right direction.

Thanks a lot
Sriram Gopalan

You have 2 choices. You can write your own code to setup a lattice of atoms in
the shape of a cone, and input them via “read_data” into LAMMPS.

Or you can write a region_cone.cpp file, using region_sphere or region_block as
a starting point. Then a “cone” region will become part of LAMMPS itself
as discussed in Section_modify of the manual. The
region_cone.cpp file simply needs to a) read the parameters that define the cone,
b) define the extent of the cone, and c) determine whether a point x,y,z is inside/outside
the cone.