Re: [Wien] Band labeling
This is a type of textbook question, that means the complete answer takes more than one textbook it will depend on how much you know about electronic structure, symmetry and group theory, as well as topology. In the forum one can answer how to do things or comment on small questions, however, why you calculated the band structure of something is a question that you have to ask yourself. In short, the irreducible representation tells you which symmetry a band has, this has mostly nothing to do with its shape. In an anylysis of the electronic structure of a semiconductor about its topological character (trivial or non trivial) you might like to check first whether band inversion occurs that is whether the energies of bands with distinguished energies are "regular" or "reversed", more details will depend on the system you are looking on, and its impossible to give here all possibilities for every crystal structiure that might occur. In certain cases you will have to check the symmetry of the bands not only at Gamma but also at other high symmetry points. Therfore, please check the textbooks and literature. Ciao Gerhard DEEP THOUGHT in D. Adams; Hitchhikers Guide to the Galaxy: "I think the problem, to be quite honest with you, is that you have never actually known what the question is." Dr. Gerhard H. Fecher Institut of Inorganic and Analytical Chemistry Johannes Gutenberg - University 55099 Mainz and Max Planck Institute for Chemical Physics of Solids 01187 Dresden Von: wien-boun...@zeus.theochem.tuwien.ac.at [wien-boun...@zeus.theochem.tuwien.ac.at] im Auftrag von emami seyyed amir abbas [a.a.em...@birjand.ac.ir] Gesendet: Montag, 26. Oktober 2015 20:57 An: wien@zeus.theochem.tuwien.ac.at Betreff: Re: [Wien] Band labeling Thank you very much for your helpful responds. What i realized is that for obtaining more details such as band labeling i need to run irrep. As you said for topological characterization, it is necessary to obtain band structures in irreducible representation. Is there any difference in shape of bands between normal band and ones obtained in irreducible? In other words why you mentioned it is requires to plot the bands in irreducible representations. I will be very grateful if i find my answer. Thanks ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
Re: [Wien] Band labeling
I guess that for the "topological" characterisation you need the irreducible representation of the bands and not just their number e.g.: Gamma 6 (G6) means you have a e1/2 band, etc. see below In the output of irrep you will find something like: The point group is Td 24 symmetry operations in 5 classes Table 81 on page 88 in Koster et al [7] Table 73.4 on page 637 in Altmann et al [8] E 8C3 3C2 6IC4 6IC2` ... -- G6E1/2 2 1 0 /20 G7E5/2 2 1 0-/20 G8F3/2 4-1 0 0 0 etc and then you find (where 51 to 59 is the "Bandindex" of some bands at the Gamma-point (0,0,0) that I selected to be in the vicinity of the Fermi energy, as an example) bnd ndg eigval E2IC4 C2 2C2` 2IC2" ... ... 51 2 0.505713 2.00+0.00i 1.00+0.00i 0.00+0.00i 1.41+0.00i 0.00+0.00i =G6 53 2 0.540351 2.00+0.00i 1.00+0.00i 0.00+0.00i -1.41+0.00i 0.00+0.00i =G7 55 4 0.594669 4.00+0.00i -1.00+0.00i 0.00+0.00i 0.00+0.00i 0.00+0.00i =G8 59 2 0.651442 2.00+0.00i 1.00+0.00i 0.00+0.00i -1.41+0.00i 0.00+0.00i =G7 ... I guess the Band index -- here 51 etc. -- has not much meaning other than it is the number of a band with 1 being the number of the lowest state wherever Wien2k starts to count in the energy window, if you start at the bottom of the valence band you will have different numbers. as I told before you have to run lapw1, irrep etc. for 1 k-point with the correct switches ! Be sure to read and understand the textbooks [7,8] that are cited by Wien2k and that are given above. Ciao Gerhard DEEP THOUGHT in D. Adams; Hitchhikers Guide to the Galaxy: "I think the problem, to be quite honest with you, is that you have never actually known what the question is." Dr. Gerhard H. Fecher Institut of Inorganic and Analytical Chemistry Johannes Gutenberg - University 55099 Mainz and Max Planck Institute for Chemical Physics of Solids 01187 Dresden Von: wien-boun...@zeus.theochem.tuwien.ac.at [wien-boun...@zeus.theochem.tuwien.ac.at] im Auftrag von Gavin Abo [gs...@crimson.ua.edu] Gesendet: Montag, 26. Oktober 2015 10:24 An: A Mailing list for WIEN2k users Betreff: Re: [Wien] Band labeling Take the TiC calculation for example (TiC.tar.gz). In TiC.tar.gz, there is the file "TiC.spaghetti_ene". In that file, you should see the lines: bandindex: 5 ... 0.0 0.0 0.0 1.20853 -12.4 ... bandindex: 6 ... 0.0 0.0 0.0 1.20853 0.66740 ... bandindex: 7 ... 0.0 0.0 0.0 1.20853 0.66740 ... where Gamma is (0, 0, 0) [ http://www.cryst.ehu.es/cgi-bin/cryst/programs/nph-kv-list?gnum=225=optimized ] [cid:part1.06040700.06010608@crimson.ua.edu] ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
Re: [Wien] Band labeling
Take the TiC calculation for example (TiC.tar.gz). In TiC.tar.gz, there is the file "TiC.spaghetti_ene". In that file, you should see the lines: bandindex: 5 ... 0.0 0.0 0.0 1.20853 -12.4 ... bandindex: 6 ... 0.0 0.0 0.0 1.20853 0.66740 ... bandindex: 7 ... 0.0 0.0 0.0 1.20853 0.66740 ... where Gamma is (0, 0, 0) [ http://www.cryst.ehu.es/cgi-bin/cryst/programs/nph-kv-list?gnum=225=optimized ] ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
Re: [Wien] Band labeling
select 1 k-point (Gamma point) and use irrep see the manual for the correct switches Ciao Gerhard DEEP THOUGHT in D. Adams; Hitchhikers Guide to the Galaxy: "I think the problem, to be quite honest with you, is that you have never actually known what the question is." Dr. Gerhard H. Fecher Institut of Inorganic and Analytical Chemistry Johannes Gutenberg - University 55099 Mainz and Max Planck Institute for Chemical Physics of Solids 01187 Dresden Von: wien-boun...@zeus.theochem.tuwien.ac.at [wien-boun...@zeus.theochem.tuwien.ac.at] im Auftrag von emami seyyed amir abbas [a.a.em...@birjand.ac.ir] Gesendet: Montag, 26. Oktober 2015 04:40 An: wien@zeus.theochem.tuwien.ac.at Betreff: [Wien] Band labeling Dear users I am trying to label the band structures (i.e. gamma 6, gamma 7 etc). In fact, for investigation of the topological properties of compounds, it is required to specify the band index. Now how can i label the band structures? Any suggestions will be appreciate in advanced. ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
Re: [Wien] Band labeling
Thank you very much for your helpful responds. What i realized is that for obtaining more details such as band labeling i need to run irrep. As you said for topological characterization, it is necessary to obtain band structures in irreducible representation. Is there any difference in shape of bands between normal band and ones obtained in irreducible? In other words why you mentioned it is requires to plot the bands in irreducible representations. I will be very grateful if i find my answer. Thanks ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
[Wien] Band labeling
Dear users I am trying to label the band structures (i.e. gamma 6, gamma 7 etc). In fact, for investigation of the topological properties of compounds, it is required to specify the band index. Now how can i label the band structures? Any suggestions will be appreciate in advanced. ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
