strain in graphene

[shivgy]

I've applied uniaxial strain(20%) in 2-d graphene and i'm getting a bandstructure (file attached) I'm not sure if the result is correct or not.

If my result is correct then, please tell me why I am getting a w shape at K-point near fermi level.

[zh]

First, you needs to check the parameters used in your input file or how you input file.   List the important parameters: type of pseudopotential,  exchange-correlation functional, basis set, the k-mesh size used in the self-consistent calculations.

Second, you may choose an alternative pseudopotential (e.g. a harder pseudopotential with short cutoff radii) to re-run the band structure of graphene under an uniaixial strain of 20%.


Please read the following papers for the band structure of graphene under strain"
http://journals.aps.org/prb/abstract/10.1103/PhysRevB.80.167402
http://journals.aps.org/prb/abstract/10.1103/PhysRevB.81.241412
http://journals.aps.org/prb/abstract/10.1103/PhysRevB.78.075435
http://journals.aps.org/prb/abstract/10.1103/PhysRevB.80.045401

Particularly for the first one, the authors admitted that the band gap of graphene under strain is caused an insufficient k-mesh size.