Thermal expansion of Single Wall Carbon nanotube

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1

I’m trying to calculate the axial and radial expansion coefficients of single wall carbon nanotubes, and am having trouble with one of the steps.

I want to partition the single wall nanotube into cylindrical disks of width (delta-z) along the axis of the nanotube.

However, before I can use the “cylindrical” style of the region command, I need to have a lattice first. I input the coordinates for the nanotube atoms using a data file without the use of a lattice.

How can I go about inputting a lattice that matches the geometry of the nanotube in order to begin partitioning the tube into disks?

Also can I create a custom lattice in order to create the tubular cylindrical unit cell that represents nanotube lattices?

A simplified lammps input script and data file are attached.

Thanks,

v/r,

dc

twelve-one-one-swnt.data (24.9 KB)

twelve-one-chirality-nvt-swnt.lmp (2.84 KB)

2

I'm trying to calculate the axial and radial expansion coefficients of
single wall carbon nanotubes, and am having trouble with one of the steps.

I want to partition the single wall nanotube into cylindrical disks of
width (delta-z) along the axis of the nanotube.

However, before I can use the "cylindrical" style of the region command, I
need to have a lattice first. I input the coordinates for the nanotube
atoms using a data file without the use of a lattice.

you *don't* need to define a lattice.
just add "units box" to your region
command and you should be fine.

have a closer look at the docs.

axel.

ps.: i would have assigned different atom types
to the segments of the SWCNT in the data file.
that can be used for a lot of other useful things later on.

3

Thanks for your help and additional guidance.

v/r,

dc