Hello Everyone
I want to mix Carbon Nanotube in Aluminum. Please suggest how can I make such composite in LAMMPS.
Also please suggest the apt potential.
Thanks
Hi
Lammps doesn’t make composite for you. You create initial structure first using other software such as vmd.
and learn simulation you want using Lammps. and potential also depends on what type of simulation and what type of material you are simulating.
Justin
It's not clear how you want to mix aluminum.
I just posted an example of how to build graphene and nanotubes (mixed
with water) on the moltemplate web page. Starting with a graphene
unit cell, you can easily build arbitrary curved or flat 2-D surfaces.
In that example, the carbon atoms are held motionless and the other
atoms are allowed to move.
You can surround the nanotube with water or aluminum in a crude way by
creating a crystal of aluminum and cutting a rectangular shaped hole
where you want the nanotube to go. (Similarly you can fill the tube
with long-thin rectangular boxes filled with atoms.)
If you need to explicit bonds between the carbon atoms, then there
are currently other programs that may be more convenient to use for
this purpose. Unfortunately, moltemplate does not yet generate bonds
automatically (by distance or PDB-atom-name). (A future feature I
hope.)
If you need a bonded crystalline periodic system, the "Nanotube
Builder" and "topotools" by Axel (and Robert) plugins for VMD can make
bonded graphene and nanotubes. (I don't know if these generated
objects can span periodic boundaries.) It can also "solvate" a
molecule by surrounding it by water (or an aluminum crystal unit
cell).
I hope this gets you started.
Cheers
Andrew
The web page I was talking about is:
(I forgot to mention this.)
The carbon-nanotube/graphene example is the 3rd or 4th example (scroll
down). A more complete version (including README files) is bundled in
the examples download (upper-left).
Cheers
Andrew
Another nanotube/graphene builder option.
http://turin.nss.udel.edu/research/tubegenonline.html
v/r,
dc
Thanks Andrew Sir
I got some idea…
If I talk of potential then please tell me whether I have to use different potential i.e. for CNT (tersoff), for Aluminum and interaction between Al and CNT (which is not correct I think)…or there might exist single potential which describes interactions in such composite.
It’s not clear how you want to mix aluminum.
A rectangular matrix of Aluminum in which at center CNT is inserted.
I got some idea...
If I talk of potential then please tell me whether I have to use different
potential i.e. for CNT (tersoff), for Aluminum and interaction between Al
and CNT (which is not correct I think)....or there might exist single
potential which describes interactions in such composite.
Unfortunately I don't know what kind of force-fields people use to
simulate carbon nanotubes or aluminum. (Ayub told me the parameters
which Laurent Joly used in his recent JCP paper on carbon nanotube
wetting. I would not have posted this example without this help. I
can't recommend a force field for aluminum or nanotubes.)
It's not clear how you want to mix aluminum.
A rectangular matrix of Aluminum in which at center CNT is inserted.
This should not be too hard to do, if you know the crystal structure
of Aluminum.
1) You could define a new type of "molecule" consisting of a long thin
rectangular box filled with Aluminum atoms. (In the example below, I
call this "AluminumNanotubeBox". Assume, for the sake of example,
that the long axis of these rectangular boxes points in the Z
direction.)
2) cut a rectangular hole (or multiple holes, if you want a rounder
shape) down the center axis of this box.
3) Then you can put a carbon nanotube in that hole.
For example I cut a hole in a box of solvent:
http://www.moltemplate.org/images/translocation/solvent.jpg
and inserted a polymer in one of them:
http://www.moltemplate.org/images/translocation/polymer.jpg
as shown here:
http://www.moltemplate.org/images/translocation/walls+solvent+polymer_t=0.jpg
(In that example, I also added two walls, shown in purple. Ignore them)
Once you have built this, you can make many copies of these long
rectangles, side-by-side:
4) You an use a command like this:
boxes=new AluminumNanotubeBox [10].move(20,0,0)
[10].move(0,20,0)
This would create a two-dimensional arrays of "AluminumNanotubeBoxes"
(arranged in the XY plane, all pointing in the Z direction).
I don't have time to set this up for you, but I hope this gives you
some idea how to set up the geometry at least. (I don't have the
expertise to help with the force-field.)
Good luck
Andrew
Thanks Andrew Sir
I got some idea...
If I talk of potential then please tell me whether I have to use different
potential i.e. for CNT (tersoff), for Aluminum and interaction between Al
and CNT (which is not correct I think)....or there might exist single
potential which describes interactions in such composite.
this is a question, which is answered by researching the available literature
looking for somebody having done the same or something similar.
in MD simulations, there is no software where you can enter
"I want to do a simulation of XXX in YYY with ZZZ" and then
you get a set of files that does all that you want.
actually, doing the simulation itself is the smallest part
(and the simplest) of the work. the hard part is to plan it;
to come up with a suitable model and strategy and to
find a good way to extract useful information from the
simulation data. this takes time, consideration, awareness
of the work of others and thinking. this cannot be easily
solved by asking somebody "how do i do this?". since
it is hard work, nobody will do it for you.
as for the technical question of setting up a system.
if your plan is to embed a carbon nanotube into amorphous
or crystalline aluminum, you can consider using this
strategy:
https://sites.google.com/site/akohlmey/software/topotools/topotools-tutorial---various-tips-tricks#TOC-Combine-multiple-data-files-with-overlap-detection-and-removal
however, even here you will have to experiment and make
decisions, i.e. how much space will be needed and what
is too little or too much overlap. ...and after that, you will
probably have to do a *very* careful relaxation.
solids don't as easily relax as liquids.
axel.