Double Walled Naontubes X(n1,0)@Y(n2>>n1,0)
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Good evening,
please how to write the input to design a double walled from a slab between 2 different layer sheet ?
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Hello,
thank you for your question. Could you be more precise? I don't understand exactly what you mean but this is the input file for a double wall nanotube created starting from a graphene layer:title SLAB 77 2.47 1 6 0.33333333 0.6666666667 0.000000 NANOMULTI 2 WALL 1 ROLLINGV 6 6 WALL 2 ROLLINGV 12 12 NANOJMOL ENDWALL END ENDyou can have a look at the Tutorial, on the Crystal web page:
https://tutorials.crystalsolutions.eu/tutorial.html?td=mwnanotube&tf=MW_tutorialI hope it helps...
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I really appreciate your kind comment, BTW I wanna optimize a double walled Nanotube with different wall first:
- The inner wall is MgO
 - The outer wall is BeO
 - I wanna write the input from the a slab 78
 
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goodmorning,
ok... now I understand better. This is an example. I chose the space group 73 because the 78 has a mirror plane... I don't know which kind of lattice do you want to simulate ...neither if the two lattice (BeO and MgO) are commensurable ...but the idea is to build a two-layers slab, one layer of MgO and the other layer of BeO and then roll the slab
The lattice parameter is chosen randomly ...title
SLAB
73
3.47
4
8 0.5 0.0 0.000000
4 0.0 0.0 0.0000
12 0.5 0.0 2.200000
8 0.0 0.0 2.2000
SWCNT
10 10
TESTGEOM
END
END - 
Good moorning, thank you, by the way this is a Single Walled nanotube, how to do this for double Walled with different Wall, same I find in your paper: "Computational simulations of ZnO@GaN and GaN@ZnO core@shell nanotubes" : here how to fix the input
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the ZnO@GaN were done exactly in this way... if you roll up a two-layers slab you end with a double wall nanotube
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Thank you, Just CRYSTAL VLAB is working now? or it is restricted to specific use cause i didn't find where I sign up?
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hello

about VLAB I'll ask to the developer...
As for the MULTIWALL nanotubes.. there is another procedure you can follow, which use the keyword MULTIWALL. These are the steps, using as a test system a graphene sheet:
1) build a two-wall nanotube ---> see 2wall.jpg
title
SLAB
77
2.47
1
6 0.33333333 0.6666666667 0.000000
NANOMULTI
2
WALL
1
ROLLINGV
6 6
WALL
2
ROLLINGV
12 12
NANOJMOL
ENDWALL
..basis set- use the MULTIWALL.DAT file as a fort.34 and restart with the EXTERNAL keyword substituting one of the two wall with different atom(s). In this case, the inner wall becomes a nitrogen wall, see ---> ext2wall.jpg
 
title
EXTERNAL
ATOMSUBS
24
1 7
2 7
3 7
4 7
5 7
6 7
7 7
8 7
9 7
10 7
11 7
12 7
13 7
14 7
15 7
16 7
17 7
18 7
19 7
20 7
21 7
22 7
23 7
24 7
END
..basis set..

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Good morning, OH that’s cool
️, here we go and that is exactly what I want…Thank you again Dr. Casassa