Hello All, In regard to the ongoing discussion about band structure, I have a query since I am newly working in this field of computational solid state physics. While calculating band structure, Is it absolutely necessary that I calculate the band structure of a unit cell and not of a supercell? If during structural relaxation I am using a supercell, will the calculated band structure of a supercell be the same as that of a unit cell band structure in that case? How do I get the unit cell parameters from the supercell relaxation output? Is there any code to extract the unit cell data from the SIESTA output files for a supercell?
Any hints in this regard is highly appreciated. Thank you in advance. Sunetra Das Dept. of Physics, MMC College, Kolkata, India. On 6 July 2017 at 01:40, Ritwik Vatsyayan <ritwikvatsya...@gmail.com> wrote: > Dear Aakanksha, > I am using XCrysDen version 1.5.60. > > > Regards, > Ritwik > > On Mon, Jul 3, 2017 at 1:53 AM, AAKANKSHA SUD <aakankshasood0...@gmail.com > > wrote: > >> Dear Ritwik >> I am happy that my suggestions were helpful to you. I was just >> wondering that how did you open .xyz file in xcrysden because such files >> cannot be opened in it. Perhaps you are using some other version.I would >> really appreciate if you could tell me that which version of xcrysden are >> you using that supports .xyz file. >> >> Thanks >> Aakanksha >> ------------------------------ >> From: Ritwik Vatsyayan <ritwikvatsya...@gmail.com> >> Sent: 7/3/2017 1:30 AM >> >> To: siesta-l@uam.es >> Subject: Re: [SIESTA-L] Plotting Bandstructure in Siesta >> >> Dear Aakanksha, >> Thank you so much for that tip. I was >> normally using the .xyz file generated from siesta run after optimizing the >> geometry, but I guess that will not give the information about the >> k-points. >> I really appreciate your time and effort in this. >> >> Best Regards, >> Ritwik >> >> On Sat, Jul 1, 2017 at 7:24 AM, AAKANKSHA SUD < >> aakankshasood0...@gmail.com> wrote: >> >>> Hi ritwik >>> Could you please elaborate the steps you followed. First you have to >>> optimise the geometry . So after optimisation you will get .xv file. There >>> is a utility in siesta xv2xsf . Use that to generate .xsf file.Now open >>> that file in xcrysden and generate the kpoints. After that do the >>> calculation for bandstructure. Hope it helps. >>> >>> Regards >>> Aakanksha >>> ------------------------------ >>> From: Ritwik Vatsyayan <ritwikvatsya...@gmail.com> >>> Sent: 7/1/2017 1:31 AM >>> To: siesta-l@uam.es >>> Subject: Re: [SIESTA-L] Plotting Bandstructure in Siesta >>> >>> Dear Aakanksha, >>> Thank you for suggesting XCrysDen. I >>> wanted to know that when you are using xcrysden to generate the k-points, >>> what is the extension of the file you use as the input? I tried using the >>> SystemLabel.xyz file, but it doesn't give me the option for making k-path. >>> Is there some other file generated by Siesta which can be used? >>> >>> Regards, >>> Ritwik Vatsyayan >>> >>> On Thu, Jun 29, 2017 at 1:59 AM, AAKANKSHA SUD < >>> aakankshasood0...@gmail.com> wrote: >>> >>>> Hi Ritwik >>>> It would be better if you use xcrysden to know the high symmetry pts. >>>> And using xcrysden you can easily generate the kpoints based on the >>>> brillouin zone.and its necessary to use a cyclic closed path. We are >>>> defining a region of brilliouin zone and by repeating it we can define >>>> whole zone so its necessary to specify the cyclic path. And specifying the >>>> number of intersections between two k points is also necessary. Regarding >>>> the reciprocal lattice vectors or fractional it depends like in which >>>> coordinates you are specifying the kpoints. I insist that you should use >>>> xcrysden or some other kpoint generating software . >>>> >>>> Hope it helps.. >>>> >>>> Regards >>>> Aakanksha >>>> ------------------------------ >>>> From: Ritwik Vatsyayan <ritwikvatsya...@gmail.com> >>>> Sent: 6/29/2017 1:32 AM >>>> To: siesta-l@uam.es >>>> Subject: [SIESTA-L] Plotting Bandstructure in Siesta >>>> >>>> Dear Siesta Users, >>>> I am working on a system with a >>>> hexagonal lattice, and I want to plot the bandstructure for the same. >>>> I read online at: https://lampx.tugraz.at/~hadle >>>> y/ss1/bzones/hexagonal.php >>>> that the high symmetry points of the first Brillouin zone of a simple >>>> hexagonal lattice are: >>>> Γ: (0,0,0) >>>> M: (1/2,0,0) >>>> K: (2/3,1/3,0) >>>> H: (2/3,1/3,1/2) >>>> A: (0,0,1/2) >>>> L: (1/2,0,1/2) >>>> These points are in the fractional format. I want to plot the >>>> bandstructure using these points. >>>> In the fdf file, we must declare the BandLinesScale. For these >>>> co-ordinates, would the format be : ReciprocalLatticeVectors or pi/a ? >>>> >>>> Also, for plotting the bandstructure, do we need to make a cyclic path, >>>> for example, Γ->M->K->Γ ? Or can we stop at Γ->M->K as well? >>>> >>>> I would be grateful if anyone can help me out in this. Thank you for >>>> your time. >>>> Regards, >>>> Ritwik Vatsyayan >>>> Pre-Final Year Undergraduate >>>> Electronics and Communication Engineering >>>> Indian Institute of Technology, Guwahati >>>> >>> >>> >> >
