Applying strain on a 2 D material  [SOLVED]

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manik
Posts: 6
Joined: Wed Nov 16, 2016 9:04 am

Applying strain on a 2 D material

Post by manik » Wed Nov 30, 2016 5:16 pm

Dear all

I followed the silicon tutorial, modified it for a monolayer MoS2 and computed its band structure.

Now i want to apply strain on monolayer and compute the band structure again as a function of strain.

My question is How can i apply strain like 1% strain.?

I tried changing the xcart in previous file by 0.01 as specified in response function tutorial but it doesnot show much difference in bandgap.?

Also in Si tutorial a non- SCF calculation is used to compute band structure. Why it is so?

I need to plot band-structures with different values of uniaxial strain?

Please help me.

Regards
Manik

ilukacevic
Posts: 271
Joined: Sat Jan 16, 2010 12:05 pm
Location: Dept. of Physics, University J. J. Strossmayer, Osijek, Croatia
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Re: Applying strain on a 2 D material  [SOLVED]

Post by ilukacevic » Thu Dec 01, 2016 8:51 am

Dear manik,

1. It seems that you misunderstood something. Strain concerns the deformation of lattice (through rprim variable), not atomic positions (xcart). If you followed the elastic response function tutorial at

http://www.abinit.org/doc/helpfiles/for-v8.0/tutorial/lesson_elastic.html#4

you could see that lattice c-axis is changed by a small percentage, after a careful relaxation of the whole unit cell. This is the way you need to follow. Do a very accurate relaxation of your unit cell. Then strain the lattice in the desired direction (as is shown in telast_4.in example) and calculate the band structure for the strained lattice.

2. If you don't understand why you need non-scf to obtain the band structure, go through the basic tutorial again

http://www.abinit.org/doc/helpfiles/for-v8.0/tutorial/lesson_base3.html.

Best regards,

Igor

manik
Posts: 6
Joined: Wed Nov 16, 2016 9:04 am

Re: Applying strain on a 2 D material

Post by manik » Thu Dec 01, 2016 12:27 pm

Thank you Igor for your reply. Now it works well. :)

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