In order to study the property of CNT, I need to optimize its structure. As we know, CNT just has periodic boundary condition in the axial direction. So I think I should use a lateral separation between tube centers to make sure that CNT do not interact with their periodic images. My work are doing with VASP.
Am I right? If I am right, how to set the seperation?
About the optimization of Nanotube
Moderators: Global Moderator, Moderator
-
lanjh
About the optimization of Nanotube
Last edited by lanjh on Wed Dec 20, 2006 2:51 am, edited 1 time in total.
-
tjf
- Full Member
- Posts: 107
- Joined: Wed Aug 10, 2005 1:30 pm
- Location: Leiden, Netherlands
About the optimization of Nanotube
[quote="]If I am right, how to set the seperation?[/quote"]
Assuming that you meen picking an appropriate distance, in general you need to run some calculations at different seperations to look at how far apart the nanotubes need to be to not change the energy (and/or the forces). I'd be willing to accept that different tubes would require different minimum seperations depending on whether they were metallic or not.
I'd guess that something like 10 Ang would be required. Others who have more experience with this type of system may like to comment.
Assuming that you meen picking an appropriate distance, in general you need to run some calculations at different seperations to look at how far apart the nanotubes need to be to not change the energy (and/or the forces). I'd be willing to accept that different tubes would require different minimum seperations depending on whether they were metallic or not.
I'd guess that something like 10 Ang would be required. Others who have more experience with this type of system may like to comment.
Last edited by tjf on Wed Dec 20, 2006 12:36 pm, edited 1 time in total.
-
sri123
About the optimization of Nanotube
hi..
the obsolute distance between the nanotubes will be varied with the size of the nanotubes. for larger CNT it will be increasing (say 40 Angstroms for [24 0] cnt). you have mention this seperation in the POSCAR file. for example
cnt240
1.0000
40.000000 0.0000000 0.0000000
0.0000000 40.000000 0.0000000
0.0000000 0.0000000 4.2300000
96
Direct
since nanotubes extend 1-dimensionally the above lattice parameters indicates that the CNT is extended in Z-direction and in X & Y it is separated by 40 Angstroms from other nanotubes.
hope it will help u
the obsolute distance between the nanotubes will be varied with the size of the nanotubes. for larger CNT it will be increasing (say 40 Angstroms for [24 0] cnt). you have mention this seperation in the POSCAR file. for example
cnt240
1.0000
40.000000 0.0000000 0.0000000
0.0000000 40.000000 0.0000000
0.0000000 0.0000000 4.2300000
96
Direct
since nanotubes extend 1-dimensionally the above lattice parameters indicates that the CNT is extended in Z-direction and in X & Y it is separated by 40 Angstroms from other nanotubes.
hope it will help u
Last edited by sri123 on Wed Oct 14, 2009 9:50 am, edited 1 time in total.