From kemper at qtp.ufl.edu Thu Oct 2 19:02:36 2008 From: kemper at qtp.ufl.edu (Lex Kemper) Date: Thu, 02 Oct 2008 13:02:36 -0400 Subject: [Wannier] [Fwd: Wannier90 kpoints issue] Message-ID: <48E4FEAC.8070201@qtp.ufl.edu> Hello, I get an error from wannier90 that I don't know how to fix. I am attempting to do a calculation for a relatively small system, 5 atoms, in a body-centered tetragonal lattice. When I try to create the pwscf inputfile, wannier90 gives me this error after the first 2 bvectors. kmesh_get_bvector: Not enough bvectors found I'm not sure what this means or how to fix it. Any suggestions? The (relevant) portions of the input/output are below. Thanks, Lex Kemper University of Florida -----------------------input---------------------------------- num_bands = 25 num_wann = 16 num_iter = 10000 begin unit_cell_cart bohr 3.69136240 -3.691362400 11.19734109 3.69136240 3.691362400 11.19734109 -3.69136240 -3.691362400 11.19737870 end unit_cell_cart begin atoms_cart ang Sr 0.000000000 0.000000000 0.000000000 Fe 1.953385000 0.000000000 2.962700000 Fe 0.000000000 1.953385000 2.962700000 As 0.000000000 0.000000000 4.192813040 As 1.953385000 1.953385000 1.732586960 end atoms_cart mp_grid : 4 4 4 begin kpoints 0 0 0 0 0 0.25 etc end kpoints ---------------------------------------------------- ----------------output----------------------------- *---------------------------------- K-MESH ----------------------------------* +----------------------------------------------------------------------------+ | Distance to Nearest-Neighbour Shells | | ------------------------------------ | | Shell Distance (Ang^-1) Multiplicity | | ----- ----------------- ------------ | | 1 0.265096 2 | | 2 0.423354 6 | | 3 0.423356 2 | | 4 0.530192 2 | | 5 0.565491 2 | | 6 0.565492 4 | | 7 0.565494 2 | | 8 0.568613 4 | | 9 0.627372 4 | | 10 0.627374 4 | | 11 0.775166 2 | | 12 0.775168 4 | +----------------------------------------------------------------------------+ | | | Complete list of b-vectors and their lengths | | | +----------------------------------------------------------------------------+ | b-vector 1 : ( 0.000001 0.000000 0.265096 ) 0.265096 | | b-vector 2 : ( -0.000001 0.000000 -0.265096 ) 0.265096 | Exiting....... kmesh_get_bvector: Not enough bvectors found -------------------------------------------------------------------------------- From jry20 at cam.ac.uk Fri Oct 3 11:45:52 2008 From: jry20 at cam.ac.uk (Jonathan Yates) Date: Fri, 3 Oct 2008 10:45:52 +0100 Subject: [Wannier] [Fwd: Wannier90 kpoints issue] In-Reply-To: <48E4FEAC.8070201@qtp.ufl.edu> References: <48E4FEAC.8070201@qtp.ufl.edu> Message-ID: On 2 Oct 2008, at 18:02, Lex Kemper wrote: > > Hello, > > I get an error from wannier90 that I don't know how to fix. I am > attempting to do a calculation for a relatively small system, 5 atoms, > in a body-centered tetragonal lattice. When I try to create the pwscf > inputfile, wannier90 gives me this error after the first 2 bvectors. > > kmesh_get_bvector: Not enough bvectors found > > I'm not sure what this means or how to fix it. Any suggestions? > > The (relevant) portions of the input/output are below. > > | Distance to Nearest-Neighbour Shells | > | ------------------------------------ | > | Shell Distance (Ang^-1) Multiplicity > | ----- ----------------- > ------------ | > | 1 0.265096 > 2 | > | 2 0.423354 > 6 | > | 3 0.423356 > 2 | > | 4 0.530192 > 2 | Lex, The short answer to your question is that you either need to specify the lattice vectors to greater precision, or set kmesh_tol=0.00001 (10x lower than the default) The former is aesthetically 'nicer' but no harm will come from the latter. The error comes from the part of w90 which sets up the finite difference formula (B1 in MV). It has to analyse the lattice of kpoints to find shells of nearest neighbours. From the section of output file above you can see that shells 2 and 3 are very nearly degenerate: in fact if you think about the symmetry of your lattice they should be degenerate (I'm guessing that the finite precision in your lattice vectors has broken this). In this circumstance w90 gets a bit confused, hence the error. We could code it to be more robust to this, although this is messy (and hides the real problem which is the lack of precision) so I prefer not to. But I will improve the error message to make it more helpful! I assume you are using pwscf. What would be useful is a program/ script to convert from pwscf input to w90 input keeping 'enough' precision. Any volunteers? Jonathan General note: I'm in the middle of transferring institutions. If you've sent me mail in the last couple weeks and I haven't replied - sorry, I am (slowly) catching up. -- Department of Materials University of Oxford Parks Road, Oxford, OX1 3PH, UK http://www.tcm.phy.cam.ac.uk/~jry20/ From kemper at qtp.ufl.edu Wed Oct 8 21:03:27 2008 From: kemper at qtp.ufl.edu (Lex Kemper) Date: Wed, 08 Oct 2008 15:03:27 -0400 Subject: [Wannier] Reduced unit cell issues Message-ID: <48ED03FF.8000906@qtp.ufl.edu> Hey everyone, I'm attempting to calculate the Fermi surface / wannier band structure for a body-centered tetragonal system. The bct system is the primitive unit cell for one that I've calculated before, which is tetragonal (a =b < c). The tetragonal system finishes fine -- I end up with a real Hamiltonian. When I try the bct system, it always ends up complex. Any suggestions? Thanks, Lex Kemper University of Florida From marzari at MIT.EDU Thu Oct 9 12:52:57 2008 From: marzari at MIT.EDU (Nicola Marzari) Date: Thu, 09 Oct 2008 13:52:57 +0300 Subject: [Wannier] Reduced unit cell issues In-Reply-To: <48ED03FF.8000906@qtp.ufl.edu> References: <48ED03FF.8000906@qtp.ufl.edu> Message-ID: <48EDE289.2020801@mit.edu> Lex Kemper wrote: > Hey everyone, > > I'm attempting to calculate the Fermi surface / wannier band structure > for a body-centered tetragonal system. The bct system is the primitive > unit cell for one that I've calculated before, which is tetragonal (a =b > < c). The tetragonal system finishes fine -- I end up with a real > Hamiltonian. When I try the bct system, it always ends up complex. Any > suggestions? Dear Lex, of course the first thing to check out would be the WFs themselves - are those real ? If they are not, I presume the code gots stuck in a false minima, and you should use the initial projections as a hint for the WFs procedure (given also that you have a good sense from the tetragonal calculations, of what the WFs look like). If you are using projections, and the WFs end up being complex, it might point out to a mismatch in what you and the code think abut the projection centers in absolute/relative coordinates. nicola --------------------------------------------------------------------- Prof Nicola Marzari Department of Materials Science and Engineering 13-5066 MIT 77 Massachusetts Avenue Cambridge MA 02139-4307 USA tel 617.4522758 fax 2586534 marzari at mit.edu http://quasiamore.mit.edu From nafiserb at gmail.com Tue Oct 14 14:27:49 2008 From: nafiserb at gmail.com (nafise rezaei) Date: Tue, 14 Oct 2008 15:57:49 +0330 Subject: [Wannier] fermi-surafec Message-ID: <785b26a90810140527p7b92ff87o67031c14dbbcbbcb@mail.gmail.com> Dear all; I calculation MLWF for my case and plot fermi surface. fermi surface can be useful for predicting the electical,magnetic properties of metals & halfmetal. my system is half-metal and I want to interpretation of fermi surface and predict properties of my case. would you please guid me introduce some paper for interpretation of fermi surface? Thanke you in advance, Nafise. From f_mirjani at ph.iut.ac.ir Thu Oct 16 11:23:31 2008 From: f_mirjani at ph.iut.ac.ir (fatemeh.mirjani) Date: Thu, 16 Oct 2008 12:53:31 +0330 (IRST) Subject: [Wannier] Muffin-Tin part of Mmn Message-ID: <8284317.166841224149011009.JavaMail.root@mta.iut.ac.ir> Dear Wannier90 users & developers; About some days ago I sent an email to the mailing-list and asked about my problems in the interface code between WIEN2k & Wannier90. the way that was suggested to me by Prof.Posternak was checking Mmn matrix when we let b=0. Now I've found the bugs of my code . So Mmn (when b=0) is equal to 1 for diagonal components and is equal to 0 for off-digonal (test in Silicon). when I put b/=0 (non-zero) the Interstitial part of Mmn is real but Muffin-Tin part is complex and with regard to the inversion symmetry of Silicon I think this result is not correct. The MT part of Mmn should be real too. Also another point which shows the correctness of Mmn is that "the sum of centers of 4 WFs of silicon should be the same as the sum of 4 bond centers." I've put the centers on the Silicons atoms so sum of centers should be (0 0 0) in silicon.wout but this is for example (-0.811438,-1.254249,-0.817672) in silicon.wout . I don't know why my code works correctly when b=0 and the result is not true when b/=0 ? Plesae let me know if there is someone who has any suggestion. I'm anxiously looking forward your reply and guidelines. Best, Fatemeh -- +------------------------------------------------------------------------------+ |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 ans341 at mail.usask.ca Fri Oct 24 23:38:29 2008 From: ans341 at mail.usask.ca (ans341 at mail.usask.ca) Date: Fri, 24 Oct 2008 15:38:29 -0600 Subject: [Wannier] benzene example Message-ID: <1224884309.4902405594ce2@webmail.usask.ca> Dear Wannier90 users, I have been learning how to use Wannier90 program (version 1.1) and consequently I have gone throught the examples provided with the program. What puzzles me is the benzene example (/examples/example12/). I have managed to calculate the valence states, but they are not what I expected. I was hoping to see a pi ring around the ring but I only got this kind of MLWFs: xxx xxxxx xxxxx oo xxxxx oo xxxxxxx ooo_xxxxx_ooo xxxxxxxxx _______ oo/ xxxxx \oo xxo/oxxxxxo\oxx / o\ xxxx oo xxxxx oo xxxo/oxxxxxxxo\oxxx / oo \ xxxxxx 3x / xxx \ 6x xxo/oxxxxxxxxxo\oxx 6x / ooo \xxxxxxxx \ / \ / \ ooo /xxxxxxxx \ / \ / \ oo / xxxxxx \_______/ \_______/ \______o/ xxxx Could someone provide me with the correct results of the example 12 so that I could try to reproduce them? In addition, I would like to know if there is a way to use the PWscf wave functions obtained from a parallel run (say, with 16 processors) with less (say, 8) prosessors for pw2wannier.x? According to my short experience, it does not work without something extra. Thank you for your help! Anna Sankari From jry20 at cam.ac.uk Sat Oct 25 01:04:33 2008 From: jry20 at cam.ac.uk (Jonathan Yates) Date: Sat, 25 Oct 2008 00:04:33 +0100 (BST) Subject: [Wannier] benzene example In-Reply-To: <1224884309.4902405594ce2@webmail.usask.ca> References: <1224884309.4902405594ce2@webmail.usask.ca> Message-ID: On Fri, 24 Oct 2008, ans341 at mail.usask.ca wrote: > xxx > xxxxx xxxxx > oo xxxxx oo xxxxxxx > ooo_xxxxx_ooo xxxxxxxxx _______ > oo/ xxxxx \oo xxo/oxxxxxo\oxx / o\ xxxx > oo xxxxx oo xxxo/oxxxxxxxo\oxxx / oo \ xxxxxx > 3x / xxx \ 6x xxo/oxxxxxxxxxo\oxx 6x / ooo \xxxxxxxx > \ / \ / \ ooo /xxxxxxxx > \ / \ / \ oo / xxxxxx > \_______/ \_______/ \______o/ xxxx > > Could someone provide me with the correct results of the example 12 so that I > could try to reproduce them? Anna, I like the ascii-art wannier functions! As far as I can tell you do have the 'correct' answer. See Partly Occupied Wannier Functions K. S. Thygesen, L. B. Hansen, and K. W. Jacobsen http://link.aps.org/abstract/PRL/v94/e026405 They are using a slightly difference formalism to construct their MLWF - but actually they turn out pretty much the same as those from w90. There is some discussion in the paper. Possibly you expected to see sigma and pi like orbitals. The fact that you don't is known in the chemistry literature, where Wannier functions in the limit of a finite system are called Foster-Boys orbitals. Chemists have other types of localised orbitals such as Edmiston-Ruedenberg which do preserve the pi-sigma distinction. I'm not an expert in this - but I though I could give you some terms to start a literature search with. I suspect others here know more about this. > In addition, I would like to know if there is a way to use the PWscf wave > functions obtained from a parallel run (say, with 16 processors) with less > (say, 8) prosessors for pw2wannier.x? According to my short experience, it does > not work without something extra. See http://www.democritos.it/pipermail/wannier/2008-June/000151.html and the response. If you change the number of processors you need to set wf_collect=.true. for the nscf calculation. Yours Jonathan -- Department of Materials University of Oxford Parks Road, Oxford, OX1 3PH, UK http://www.tcm.phy.cam.ac.uk/~jry20/ From nafiserb at gmail.com Wed Oct 29 13:02:52 2008 From: nafiserb at gmail.com (nafise rezaei) Date: Wed, 29 Oct 2008 15:32:52 +0330 Subject: [Wannier] effectiv mass in PRB, 75, 195121 paper Message-ID: <785b26a90810290502h334961eboee5800a968d3ba76@mail.gmail.com> Dear Jonathan; Would you please tell me that what component of inverse effective mass tensor(\mu_xx or \mu_xy or ...) have been plotted in figure2 of YWVS paper-Phys. Rev. B 75, 195121(2007)-? Best Regards Nafise