From cbh31 at cam.ac.uk Sat Sep 12 00:49:13 2015 From: cbh31 at cam.ac.uk (Bang C. Huynh) Date: Sat, 12 Sep 2015 00:49:13 +0200 Subject: [Wannier] Analysing BoltzWann outputs Message-ID: Dear all, I am having a few questions regarding how to analyse the outputs of BoltzWann correctly. 1. When the thermoelectric results are calculated over a range of chemical potentials, at what value of chemical potential should I pick out the thermoelectric properties such that they are reasonably closest to the real physical properties of the system? Is this in any way related to the Fermi level calculated by the nscf calculation by QE? I haven't obtained any experimental data yet and I am trying to use BoltzWann to help guide my syntheses, so I would like to get as much meaningful physical insights from these calculations as possible. 2. How should I treat the effect of anisotropy as BoltzWann outputs the thermoelectric properties as tensors where, in most, if not all, cases, the xx, yy and zz components are not identical / vastly different. I think anisotropy only applies to single crystals, and my system consists of polycrystalline grains, so some averaging must have taken place in reality to result in apparent isotropy. But I am not sure how to process BoltzWann data to take into account this averaging. My ultimate goal is to investigate how the figure of merit ZT varies with temperature, so perhaps I will need to average the Seebeck coefficient, electrical conductivity and thermal conductivity. My apology of these questions seem elementary, as I have not had much experience with solid-state physics/chemistry. I really look forward to your reply. Thank you very much. Regards, -- BANG C. HUYNH Peterhouse University of Cambridge CB2 1RD The United Kingdom -------------- next part -------------- An HTML attachment was scrubbed... URL: From jrxu123 at 163.com Sun Sep 20 13:48:03 2015 From: jrxu123 at 163.com (=?GBK?B?0Oy98MjZIM2svMO089Gn?=) Date: Sun, 20 Sep 2015 19:48:03 +0800 (CST) Subject: [Wannier] bandstructure of graphene/h-BN Message-ID: <5239cd9a.6551.14fea951559.Coremail.jrxu123@163.com> Dear Wannier90's users and developers: Recently, I have been fitting the bandstructure of bilayer graphene/h-BN using vasp2wannier90 code. The bandstructure below (figure1) is similar to DFT result's when I use fewer Kpoints (eg. KPOINTS: 5*5*1). , figure 1 calculated file as below: INCAR step3:GW calculation ALGO = GW0 ; LSPECTRAL = .TRUE. ; NOMEGA = 60 NBANDS=72 #LRPA = .FALSE. LWANNIER90=.TRUE. KPOINTS Automatic mesh 0 G 5 5 1 POSCAR grephene-BN 1*1*1 1.0 2.1304224933097191 -1.23 0.0 0.0 2.46 0.0 0.0 0.0 20.52 2 1 1 d 0.0000000000000000 -0.0000000000000000 0.5833333333333333 0.3333333333333333 0.6666666666666667 0.5833333333333333 0.0000000000000000 -0.0000000000000000 0.4166666666666667 0.6666666666666667 0.3333333333333333 0.4166666666666667 Wannier90.win num_wann = 12 ! set to NBANDS by VASP num_bands= 24 exclude_bands: 25-72 Begin Projections #C:sp2;pz #C:l=1,mr=1 #B:l=1,mr=1 #N:l=1,mr=1 #C:sp2;pz #B:sp2;pz #N:sp2;pz C:l=1 B:l=1 N:l=1 End Projections #dis_froz_max=9 dis_num_iter=1000 guiding_centres=true use_bloch_phases = T begin unit_cell_cart 2.1304225 -1.2300000 0.0000000 0.0000000 2.4600000 0.0000000 0.0000000 0.0000000 20.5200000 end unit_cell_cart begin atoms_cart C 0.0000000 0.0000000 11.9700000 C 0.7101408 1.2300000 11.9700000 B 0.0000000 0.0000000 8.5500000 N 1.4202817 0.0000000 8.5500000 end atoms_cart mp_grid = 5 5 1 But when I increase Kpoints to 20*20*1 in order to get high-quality results, I get wrong results (figure2) The calculated files are as below: INCAR step3:GW calculation ALGO = GW0 ; LSPECTRAL = .TRUE. ; NOMEGA = 120 NBANDS=72 #LRPA = .FALSE. LWANNIER90=.TRUE. KPOINTS Automatic mesh 0 G 20 20 1 Why the results are wrong? How should I adjust the parameters? I look forward to receive your reply. Thanking you and with regards. Kinglong Xu. -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: QQ??20150920170105.png Type: image/png Size: 16762 bytes Desc: not available URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: QQ??20150920170321.png Type: image/png Size: 23619 bytes Desc: not available URL: From huanghq at phys.tsinghua.edu.cn Sun Sep 20 14:06:11 2015 From: huanghq at phys.tsinghua.edu.cn (huanghq) Date: Sun, 20 Sep 2015 20:06:11 +0800 Subject: [Wannier] bandstructure of graphene/h-BN References: Message-ID: <201509202006045199255@phys.tsinghua.edu.cn> Dear Jinrong, You should set the kpoint_path in the wannier90.win file. Huaqing -- Huaqing Huang Department of Physics Tsinghua University Beijing, 100084 P.R.CHINA Tel: 86-10-62772784 http://sparc.phys.tsinghua.edu.cn/~huanghq/ From: wannier-request Date: 2015-09-20 19:48 To: wannier Subject: Wannier Digest, Vol 92, Issue 2 Send Wannier mailing list submissions to wannier at quantum-espresso.org To subscribe or unsubscribe via the World Wide Web, visit http://mailman.qe-forge.org/cgi-bin/mailman/listinfo/wannier or, via email, send a message with subject or body 'help' to wannier-request at quantum-espresso.org You can reach the person managing the list at wannier-owner at quantum-espresso.org When replying, please edit your Subject line so it is more specific than "Re: Contents of Wannier digest..." Today's Topics: 1. bandstructure of graphene/h-BN (??? ????) _______________________________________________ Wannier mailing list Wannier at quantum-espresso.org http://mailman.qe-forge.org/cgi-bin/mailman/listinfo/wannier -------------- next part -------------- An HTML attachment was scrubbed... URL: From szaboa at iis.ee.ethz.ch Mon Sep 21 11:19:04 2015 From: szaboa at iis.ee.ethz.ch (Aron Szabo) Date: Mon, 21 Sep 2015 11:19:04 +0200 Subject: [Wannier] bandstructure of graphene/h-BN In-Reply-To: <5239cd9a.6551.14fea951559.Coremail.jrxu123@163.com> References: <5239cd9a.6551.14fea951559.Coremail.jrxu123@163.com> Message-ID: <55FFCB88.9050500@iis.ee.ethz.ch> Try to use an odd mesh, like 19x19x1 or 21x21x1. Sometimes it matters a lot whether you include the Gamma point or not. But it is just a guess, I don't know for sure why you get these results. It could also be that the wavefunctions were not converged in the second case. Did you run first a self-consistent simulation then a second one with NELM set to 0 to generate the projections? Or did you do everything in one step in the second simulation too (like in the INCAR file you've attached?)? Because in the first case it is possible that VASP could not read in the WAVECAR correctly. Sometimes it does not even give a warning, and tells that it had read the WAVECAR, but still it starts from non-converged wavefunctions, and I don't know exactly why. One possible cause is that the NPAR or KPAR parameters were changed between the two runs, but sometimes even with the same setting it does not work. So you should check the eigenvalues of the VASP run whether they make sense. And I usually also set the LORBIT=10 to project the VASP wavefunctions to atomic orbitals (independently of Wannier90), and see if the bands I'm interested in really have the character I expected. Also, don't set use_bloch_phases=T if you explicitly set the projections. Best, Aron On 09/20/2015 01:48 PM, ??? ???? wrote: > Dear Wannier90's users and developers: > Recently, I have been fitting the bandstructure of bilayer > graphene/h-BN using vasp2wannier90 code. The bandstructure below > (figure1) is similar to DFT result's when I use fewer Kpoints (eg. > KPOINTS: 5*5*1). > , > figure 1 > > > calculated file as below: > *INCAR* > step3:GW calculation > ALGO = GW0 ; LSPECTRAL = .TRUE. ; NOMEGA = 60 > NBANDS=72 > #LRPA = .FALSE. > LWANNIER90=.TRUE. > *KPOINTS* > Automatic mesh > 0 > G > 5 5 1 > *POSCAR* > grephene-BN 1*1*1 > 1.0 > 2.1304224933097191 -1.23 0.0 > 0.0 2.46 0.0 > 0.0 0.0 20.52 > 2 1 1 > d > 0.0000000000000000 -0.0000000000000000 0.5833333333333333 > 0.3333333333333333 0.6666666666666667 0.5833333333333333 > 0.0000000000000000 -0.0000000000000000 0.4166666666666667 > 0.6666666666666667 0.3333333333333333 0.4166666666666667 > *Wannier90.win* > num_wann = 12 ! set to NBANDS by VASP > num_bands= 24 > exclude_bands: 25-72 > > Begin Projections > #C:sp2;pz > #C:l=1,mr=1 > #B:l=1,mr=1 > #N:l=1,mr=1 > #C:sp2;pz > #B:sp2;pz > #N:sp2;pz > C:l=1 > B:l=1 > N:l=1 > End Projections > > #dis_froz_max=9 > dis_num_iter=1000 > > guiding_centres=true > > > use_bloch_phases = T > > begin unit_cell_cart > 2.1304225 -1.2300000 0.0000000 > 0.0000000 2.4600000 0.0000000 > 0.0000000 0.0000000 20.5200000 > end unit_cell_cart > > begin atoms_cart > C 0.0000000 0.0000000 11.9700000 > C 0.7101408 1.2300000 11.9700000 > B 0.0000000 0.0000000 8.5500000 > N 1.4202817 0.0000000 8.5500000 > end atoms_cart > > mp_grid = 5 5 1 > > > > > > But when I increase Kpoints to 20*20*1 in order to get high-quality > results, I get wrong results (figure2) > The calculated files are as below: > *INCAR* > step3:GW calculation > ALGO = GW0 ; LSPECTRAL = .TRUE. ; NOMEGA = 120 > NBANDS=72 > #LRPA = .FALSE. > LWANNIER90=.TRUE. > *KPOINTS* > Automatic mesh > 0 > G > 20 20 1 > > Why the results are wrong? How should I adjust the parameters? > > I look forward to receive your reply. > > Thanking you and with regards. > Kinglong Xu. > > > > > _______________________________________________ > Wannier mailing list > Wannier at quantum-espresso.org > http://mailman.qe-forge.org/cgi-bin/mailman/listinfo/wannier -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: image/png Size: 16762 bytes Desc: not available URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: image/png Size: 23619 bytes Desc: not available URL: From xubin.physics at gmail.com Mon Sep 28 22:55:31 2015 From: xubin.physics at gmail.com (Bin Xu) Date: Mon, 28 Sep 2015 15:55:31 -0500 Subject: [Wannier] symmetry in Boltzwann Message-ID: Hello, I am a new user of wannier and Boltzwann. Recently I calculated the Fermi surface and conductivity of the tetragonal phase of SrTiO3. Overall the results are very nice, but I see one minor issue, i.e. the in-plane components of the conductivity tensor (sigma_xx and sigma_yy) are not fully symmetric. The difference is not very much (can be as large as a few percent), but it would be better to know if this is caused by my faulty usage (input etc...) or symmetrization of the code. I use abinit (wannier 1.2) to generate the inputs for wannier and boltzwann, then run in stand alone mode (wannier 2.0) for the FS and transport. I've checked that the eig file is perfectly symmetric and the FS is also symmetric. It seems the tetragonal symmetry is only slightly broken in boltzwann. Thanks in advance! Bin Xu -- University of Arkansas Physics Department Fayetteville, AR 72701 USA Tel: 479-575-2019 -------------- next part -------------- An HTML attachment was scrubbed... URL: From giovanni.pizzi at epfl.ch Tue Sep 29 12:07:52 2015 From: giovanni.pizzi at epfl.ch (Giovanni Pizzi) Date: Tue, 29 Sep 2015 10:07:52 +0000 Subject: [Wannier] symmetry in Boltzwann In-Reply-To: References: Message-ID: Dear Bin Xu, as a first check, could you check if the Wannier functions you get are fully converged and if they are symmetric as expected? Then, could you provide the input files, so I can check what is the problem? It will be sufficient to have the .win file, the .chk file produced when the wannierization is reached (maybe converted to formatted form using the w90chk2chk.x command, described in the user guide) and the .eig file. Please send me also the .wout files and the output of BoltzWann so we can check if convergence is achieved, etc. As the files may be big, you can send them to me directly, and we will then report back to the mailing list with the results. Giovanni -- Giovanni Pizzi Post-doctoral Research Scientist EPFL STI IMX THEOS MXC 340 (B?timent MXC) Station 12 CH-1015 Lausanne (Switzerland) Phone: +41 21 69 31124 On 28 Sep 2015, at 22:55, Bin Xu wrote: Hello, I am a new user of wannier and Boltzwann. Recently I calculated the Fermi surface and conductivity of the tetragonal phase of SrTiO3. Overall the results are very nice, but I see one minor issue, i.e. the in-plane components of the conductivity tensor (sigma_xx and sigma_yy) are not fully symmetric. The difference is not very much (can be as large as a few percent), but it would be better to know if this is caused by my faulty usage (input etc...) or symmetrization of the code. I use abinit (wannier 1.2) to generate the inputs for wannier and boltzwann, then run in stand alone mode (wannier 2.0) for the FS and transport. I've checked that the eig file is perfectly symmetric and the FS is also symmetric. It seems the tetragonal symmetry is only slightly broken in boltzwann. Thanks in advance! Bin Xu -- University of Arkansas Physics Department Fayetteville, AR 72701 USA Tel: 479-575-2019 _______________________________________________ Wannier mailing list Wannier at quantum-espresso.org http://mailman.qe-forge.org/cgi-bin/mailman/listinfo/wannier -------------- next part -------------- An HTML attachment was scrubbed... URL: