From nafiserb at gmail.com Wed Jul 2 09:16:45 2008 From: nafiserb at gmail.com (nafise rezaei) Date: Wed, 2 Jul 2008 11:46:45 +0430 Subject: [Wannier] degenerate bands in group velocity Message-ID: <785b26a90807020016m358ccedcy5c5fd41b844a5805@mail.gmail.com> Dear Jonathan, I read your "Spectral and Fermi surface properties from Wannier interpolation" paper. but I do not know exactly, what should I do at the degenerate states.?elements off-diagonal HH_alpha(k) matrix are zero at the non-degenerate band.Would you please you explain about elements of this matrix at the degenerate states? HH_alpha(k) matrix is sum of two term: HHbar_alpha(k) term and multiplication of HH(k) and DH_alpha(k). at the degenerate states second term is zero. Are elements of first matrix (HHbar_alpha(k)) for m/=n zero? I wrote program for calculation of group velocity.at the degenerate states elements of HHbar_alpha(k) are zero for (m/=n) and non-zero for (m=n) . is this true? I appreciate your help. yours Nafise From jry20 at cam.ac.uk Wed Jul 2 13:16:35 2008 From: jry20 at cam.ac.uk (Jonathan Yates) Date: Wed, 2 Jul 2008 12:16:35 +0100 Subject: [Wannier] degenerate bands in group velocity In-Reply-To: <785b26a90807020016m358ccedcy5c5fd41b844a5805@mail.gmail.com> References: <785b26a90807020016m358ccedcy5c5fd41b844a5805@mail.gmail.com> Message-ID: <61B48FAB-CDA8-4760-BC42-0A007870C959@cam.ac.uk> On 2 Jul 2008, at 08:16, nafise rezaei wrote: Nafise, Firstly, I think that the best way to validate your implementation is to compare the analytic (ie via MLWF) gradients against numeric gradients (ie via pwscf and a spline fit) along some path in the BZ. Such as figure 2 in my paper (although this is for curvatures). Obviously you want to understand the math as well, but I found this helpful for making sure things were correct. > > I read your "Spectral and Fermi surface properties from Wannier > interpolation" paper. > but I do not know exactly, what should I do at the degenerate > states.?elements off-diagonal HH_alpha(k) matrix are zero at the > non-degenerate band.Would you please you explain about elements of > this matrix at the degenerate states? HH_alpha(k) matrix is sum of two > term: HHbar_alpha(k) term and multiplication of HH(k) and > DH_alpha(k). > > at the degenerate states second term is zero. So the second (and third) term of Eqn 26 is zero for both degenerate and non-degenerate states. > Are elements of first > matrix (HHbar_alpha(k)) for m/=n zero? In general they won't be zero (deg or non-degen) > I wrote program for calculation of group velocity.at the degenerate > states elements of HHbar_alpha(k) are zero for (m/=n) and non-zero for > (m=n) . is this true? Might be... it depends.... If you are _exactly_ at a degenerate point (2 bands cross), then the 2x2 matrix H^H_\alpha is ill-defined. You can take any combination of those (2) states at that k and they are still eigenvectors of the Hamiltonian. The "correct" choice are the vectors which diagonalise the 2x2 submatrix of H^H_\alpha, and the eigenvalues of that (2x2) matrix are the band gradients. The question is "in a numeric implementation, how close to a degenerate point do you have to be to use the degenerate theory". In my experience you rarely need to worry about degenerate points for band gradients. Take Fig 2. You will hit the degenerate point at gamma (unless you shift your kpoint grid) - but the gradients are both zero. The crossing between Gamma and K has zero measure - however fine I sampled I could not find it to sufficient accuracy that I needed to use the degenerate form - maybe this is what is happening in your case. As above: benchmark this against the numeric gradients to give you a feel for how sensitive these things are at degenerate points. If you want to compute curvatures then you need to worry more about degeneracies Jonathan -- Dr Jonathan Yates | Theory of Condensed Matter Group Corpus Christi College | Cavendish Laboratory Cambridge, CB2 1RH, UK | Cambridge, CB3 OHE, UK email jry20 at cam.ac.uk | Tel +44 (0)1223 337461 From alexandre.volgin at cea.fr Thu Jul 3 10:28:52 2008 From: alexandre.volgin at cea.fr (Alexandre Volgin) Date: Thu, 03 Jul 2008 10:28:52 +0200 Subject: [Wannier] bug in wannier90? Message-ID: <486C8DC4.6030300@cea.fr> Dear Jonathan, I think there are some problems with wannier when I am launching it in a library mode: each time I have an error message: " Exiting....... plot_wannier: file UNK00001.1 not found " With an option wannier_plot=.true UNK00* files are not created (even if I ask it in pw2wan input file). So first I tried to launch calculations without "wannier_plot" option, after what files UNK have appeared. But I must launch wannier one more time to visualize them... Is it normal? Thank you in advance. Respectfully yours, Alexandre Volgin -------------- next part -------------- A non-text attachment was scrubbed... Name: alexandre_volgin.vcf Type: text/x-vcard Size: 238 bytes Desc: not available URL: From jry20 at cam.ac.uk Thu Jul 3 12:38:13 2008 From: jry20 at cam.ac.uk (Jonathan Yates) Date: Thu, 3 Jul 2008 11:38:13 +0100 (BST) Subject: [Wannier] bug in wannier90? In-Reply-To: <486C8DC4.6030300@cea.fr> References: <486C8DC4.6030300@cea.fr> Message-ID: On Thu, 3 Jul 2008, Alexandre Volgin wrote: > Dear Jonathan, > > I think there are some problems with wannier when I am launching it in a > library mode: > each time I have an error message: > " Exiting....... > plot_wannier: file UNK00001.1 not found " > With an option wannier_plot=.true UNK00* files are not created (even if I ask > it in pw2wan input file). So first I tried to launch calculations without > "wannier_plot" option, after what files UNK have appeared. But I must launch > wannier one more time to visualize them... Is it normal? Alexandre, I understand the problem - it is actually a "bug" in pw2wannier90 not in wannier90 itself. Here is part of pw2wannier90.f90 (comment lines omitted) if(wan_mode.eq.'library') then ! call setup_nnkp call openfil_pp call ylm_expansion call compute_amn call compute_mmn call write_band call run_wannier ! <- this runs w90 if(write_unk) call write_plot ! <- this writes the UNK call lib_dealloc call stop_pp ! endif So you see we run w90 _before_ writing the UNK files. What I think we need to do is reverse the position of the two commented lines ie if(write_unk) call write_plot ! <- this writes the UNK call run_wannier ! <- this runs w90 Then plotting works fine in library mode. Arash, Stefano: Can you see any problems with making this change? - otherwise we should check it into the cvs. Jonathan -- Dr Jonathan Yates | Theory of Condensed Matter Group Corpus Christi College | Cavendish Laboratory Cambridge, CB2 1RH, UK | Cambridge, CB3 OHE, UK email jry20 at cam.ac.uk | Tel +44 (0)1223 337461 From f_mirjani at ph.iut.ac.ir Mon Jul 7 14:48:06 2008 From: f_mirjani at ph.iut.ac.ir (fatemeh.mirjani) Date: Mon, 7 Jul 2008 16:18:06 +0330 (IRST) Subject: [Wannier] num_bands Message-ID: <15549495.65201215434886522.JavaMail.root@mta.iut.ac.ir> Dear all; I put num_bands = 20 in case.win. but after running the code, the num_bands in mmn,amn,eig files is 23. Where have I made a mistake? ------------------------------------------------------------- num_bands = 20 num_wann = 20 dis_num_iter = 500 num_iter = 300 begin atoms_frac Co 0.00 0.00 0.00 Co 0.50 0.50 0.50 Mn 0.25 0.25 0.25 Si 0.75 0.75 0.75 end atoms_frac Fermi_energy 15.1458 length_unit = bohr hr_plot = true begin projections random Co:sp3 end projections begin unit_cell_cart bohr -5.325 0.000 5.325 0.000 5.325 5.325 -5.325 5.325 0.000 end unit_cell_cart mp_grid = 2 2 2 begin kpoints 0.00000000 0.00000000 0.00000000 1.250000e-01 0.00000000 0.00000000 0.50000000 1.250000e-01 0.00000000 0.50000000 0.00000000 1.250000e-01 0.00000000 0.50000000 0.50000000 1.250000e-01 0.50000000 0.00000000 0.00000000 1.250000e-01 0.50000000 0.00000000 0.50000000 1.250000e-01 0.50000000 0.50000000 0.00000000 1.250000e-01 0.50000000 0.50000000 0.50000000 1.250000e-01 end kpoints ----------------------------------------------------------------------- -- +------------------------------------------------------------------------------+ |Fatemeh Mirjani | Email: f_mirjani at ph.iut.ac.ir | |Computational Condensed Matter Research Lab. | Tel/Fax Office: +98311-3913746 | |ICTP Affiliated Center in Isfahan, | Tel Lab.: +98311-3913731 | +----------Physics Department, Isfahan University of Technology, Iran----------+ From nafiserb at gmail.com Mon Jul 14 18:18:13 2008 From: nafiserb at gmail.com (nafise rezaei) Date: Mon, 14 Jul 2008 09:18:13 -0700 Subject: [Wannier] submartix Message-ID: <785b26a90807140918p6d3551adwf56b6272ca1ce2d7@mail.gmail.com> Dear Jonathan; I have a question about making submatrix 31 equation of "spectral and fermi surface properties from wannier interpolation" paper. You suppose second and third bands are degenerate(differ less than 10-4 eV). In the same kpoint third and forth bands are degenerate, but second and forth bands aren't degenerate, ie. don't differ less than 10-4 eV.(at some of band edeges, for example) in this case how are submatrix H^W_alpha made?all of 2,3,4 bands use to make one submatrix? Is submatrix 3*3? Your reply will help me like your previous help. Regards Nafise From jry20 at cam.ac.uk Mon Jul 14 18:46:14 2008 From: jry20 at cam.ac.uk (Jonathan Yates) Date: Mon, 14 Jul 2008 17:46:14 +0100 (BST) Subject: [Wannier] submartix In-Reply-To: <785b26a90807140918p6d3551adwf56b6272ca1ce2d7@mail.gmail.com> References: <785b26a90807140918p6d3551adwf56b6272ca1ce2d7@mail.gmail.com> Message-ID: On Mon, 14 Jul 2008, nafise rezaei wrote: > I have a question about making submatrix 31 equation of "spectral and > fermi surface properties from wannier interpolation" paper. > You suppose second and third bands are degenerate(differ less than > 10-4 eV). In the same kpoint third and forth > bands are degenerate, but second and forth bands aren't degenerate, > ie. don't differ less than 10-4 eV.(at some of band edeges, for example) > in this case how are submatrix H^W_alpha made?all of 2,3,4 bands use > to make one submatrix? Is submatrix 3*3? Nafise, I think in such a situation you should make and diagonalise the 3x3 matrix. Of course, do check it numerically (as per my last email). Jonathan -- Dr Jonathan Yates | Theory of Condensed Matter Group Corpus Christi College | Cavendish Laboratory Cambridge, CB2 1RH, UK | Cambridge, CB3 OHE, UK email jry20 at cam.ac.uk | Tel +44 (0)1223 337461 From nafiserb at gmail.com Tue Jul 22 07:29:50 2008 From: nafiserb at gmail.com (nafise rezaei) Date: Tue, 22 Jul 2008 09:59:50 +0430 Subject: [Wannier] bandstructure of Pb Message-ID: <785b26a90807212229v117a7f4cmeada8d1b6b1a99de@mail.gmail.com> Dear Jonathan; thanks for your previous replies.In Pb , I run wannier90 and calculated wannier functions are good. I calculated four wannier that are atom-centered with sp3 character as you have mentioned in your paper. after wannierising , I want to plot bandstructure along the Gamma-K direction like your paper.I set this value in my input file of wannier90: G 0.00000 0.00000 0.0000 K 0.37500 -0.37500 0.000 I have four bands that the lowest band is s-like. The top three bands are p-like. but this bandsturcture is not like to FIG2,in your paper. I do not know what is problem? Did you use these values for plot bandstructure? I used fcc structure and get lattice constant equal to 4.95(Ang). Thanks for the help, I appreciate it. Regards. Nafise -------------- next part -------------- A non-text attachment was scrubbed... Name: pb_band.jpg Type: image/jpeg Size: 27419 bytes Desc: not available URL: From jry20 at cam.ac.uk Tue Jul 22 11:55:20 2008 From: jry20 at cam.ac.uk (Jonathan Yates) Date: Tue, 22 Jul 2008 10:55:20 +0100 (BST) Subject: [Wannier] bandstructure of Pb In-Reply-To: <785b26a90807212229v117a7f4cmeada8d1b6b1a99de@mail.gmail.com> References: <785b26a90807212229v117a7f4cmeada8d1b6b1a99de@mail.gmail.com> Message-ID: On Tue, 22 Jul 2008, nafise rezaei wrote: > after wannierising , I want to plot bandstructure along the Gamma-K > direction like your paper.I set this value in my input file of > wannier90: > G 0.00000 0.00000 0.0000 K 0.37500 -0.37500 0.000 > > I have four bands that the lowest band is s-like. The top three bands > are p-like. > but this bandsturcture is not like to FIG2,in your paper. I do not > know what is problem? > Did you use these values for plot bandstructure? Nafise, While Gamma and K are well defined, there are different paths between them. The actual path in figure 2 of YWVS is begin kpoint_path G 1.12500 0.07500 0.0000 K 0.12500 -0.52500 0.0000 end kpoint_path which does pass through both Gamma and K. I'm not sure why I took this slightly obscure choice - there is nothing special about it, I just needed a path in which some of the bands crossed (your more standard path would be fine). I should have explained this better in the paper. Yours Jonathan -- Dr Jonathan Yates | Theory of Condensed Matter Group Corpus Christi College | Cavendish Laboratory Cambridge, CB2 1RH, UK | Cambridge, CB3 OHE, UK email jry20 at cam.ac.uk | Tel +44 (0)1223 337461 From vranjan at gmail.com Thu Jul 31 19:35:59 2008 From: vranjan at gmail.com (Vivek Ranjan) Date: Thu, 31 Jul 2008 13:35:59 -0400 Subject: [Wannier] spread and wannier_list Message-ID: <1abcddff0807311035h5bcb051jc23129c1136e5fe8@mail.gmail.com> Hello, I am running wannier for a material. This one is giving me a lot of trouble in terms of getting all the spreads closer to 1. One or two of them always become closer to 25 angstrom. For a specific k-sampling, however, I was able to get a satisfactory result. The problem is that when the change wannier_plot_list the same starts getting a different spread. For clarity, I put 28-32 in wannier_plot_list and get a satisfactory spread. However, when I change the parameter (keeping everything else the same) to 3, 20, the spreads for a couple of WF changes. However, the total of WF-centres remain the same. I was wondering how the spreads are dependent on wannier_plot_list. I am using wannier90-1.1. -- Thank you and Regards, Vivek Ranjan -------------------- NC State University, Raleigh, NC