From szaboa at iis.ee.ethz.ch Thu Nov 12 13:06:02 2015 From: szaboa at iis.ee.ethz.ch (szaboa) Date: Thu, 12 Nov 2015 13:06:02 +0100 Subject: [Wannier] Wannier functions' spreads increasing Message-ID: <11b231f6372d6307988640a98e9106f5@iis.ee.ethz.ch> Dear Wannier90 experts, I'm facing an issue I don't understand, so I would appreciate any help. My projections produce very well localized initial states (<2 A^2 for each state), but after one iteration many of the Wannier functions' spreads become huge (>1000). Those are states whose centers are also translated to a periodic replica of the unit cell after one step. I'm using guiding centres, but it does not help. It is a supercell of a 2D heterostructure (435 atoms), with a hexagonal lattice, and a large out-of plane vacuum region. I'm using a 3x3x1 K point grid, but I've got the same problem with a 2x2x1 grid too, except that it was not the same set of Wannier functions that exhibited that weird behavior. In one case I've used 50 disentanglement steps, but it did not change anything compared to only 10 steps. I'm attaching the win and wout files. I would be grateful for any hints on what might cause this problem or how to circumvent it. Best regards, Aron Szabo IIS, ETH Zurich -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: wannier90.win URL: -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: wannier90.wout URL: From giovanni.pizzi at epfl.ch Thu Nov 12 14:11:24 2015 From: giovanni.pizzi at epfl.ch (Giovanni Pizzi) Date: Thu, 12 Nov 2015 14:11:24 +0100 Subject: [Wannier] Wannier functions' spreads increasing In-Reply-To: <11b231f6372d6307988640a98e9106f5@iis.ee.ethz.ch> References: <11b231f6372d6307988640a98e9106f5@iis.ee.ethz.ch> Message-ID: <56448FFC.7010209@epfl.ch> Dear Aron, as a first preliminary suggestion, I think that you need to make sure the convergence criterion for disentanglement is well satisfied - I have the feeling that you behavior may also be linked to the fact that you did not finish the convergence of the disentanglement, even if I have to admit I have never seen before such a behavior for my systems. Giovanni On 11/12/2015 01:06 PM, szaboa wrote: > Dear Wannier90 experts, > > I'm facing an issue I don't understand, so I would appreciate any > help. My projections produce very well localized initial states (<2 > A^2 for each state), but after one iteration many of the Wannier > functions' spreads become huge (>1000). Those are states whose centers > are also translated to a periodic replica of the unit cell after one > step. I'm using guiding centres, but it does not help. > It is a supercell of a 2D heterostructure (435 atoms), with a > hexagonal lattice, and a large out-of plane vacuum region. I'm using a > 3x3x1 K point grid, but I've got the same problem with a 2x2x1 grid > too, except that it was not the same set of Wannier functions that > exhibited that weird behavior. In one case I've used 50 > disentanglement steps, but it did not change anything compared to only > 10 steps. > I'm attaching the win and wout files. I would be grateful for any > hints on what might cause this problem or how to circumvent it. > > Best regards, > Aron Szabo > IIS, ETH Zurich > > > _______________________________________________ > Wannier mailing list > Wannier at quantum-espresso.org > http://mailman.qe-forge.org/cgi-bin/mailman/listinfo/wannier -- 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 -------------- next part -------------- An HTML attachment was scrubbed... URL: From ming_young at msn.com Sun Nov 15 08:39:04 2015 From: ming_young at msn.com (Ming Yang) Date: Sun, 15 Nov 2015 15:39:04 +0800 Subject: [Wannier] Tutorial about Wannier90 with the interface of VASP Message-ID: Dear All, I just start learning wannier90, and the code I use often is VASP. Might I ask your help to recommend some more hand-on tutorials of wannier90 interfacing with VASP? I know some examples of using wannier90 on VASP official website, but still need more examples. Thank you. Best regards, Ming Yang _________ Department of Physics, National University of Singapore -------------- next part -------------- An HTML attachment was scrubbed... URL: From szaboa at iis.ee.ethz.ch Sun Nov 15 10:02:19 2015 From: szaboa at iis.ee.ethz.ch (szaboa) Date: Sun, 15 Nov 2015 10:02:19 +0100 Subject: [Wannier] Tutorial about Wannier90 with the interface of VASP In-Reply-To: References: Message-ID: <978ac444bfb24322f0c89b385f258732@iis.ee.ethz.ch> Dear Ming, I wrote a small step-by-step tutorial on how to generate the Wannier functions of single-layer MoS2 using VASP and Wannier90. You can download it from here: https://iis.ee.ethz.ch/~szaboa/MoS2_Wannier_tutorial.zip The first few steps you might find useful if you are not familiar with VASP (ionic relaxation, band structure calculation). It also includes a Matlab script that helps visualizing the character of each state with respect to the atomic orbitals if you calculated the s,p,d -projections of the wavefunction with VASP. It helps in selecting the initial projections for the Wannier transformation. The very last step explains how to create the Hamiltonian of a finite-sized device. You probably won't need it, unless you want to do a self-consistent transport simulation. Best, Aron On 2015-11-15 08:39, Ming Yang wrote: > Dear All, > > I just start learning wannier90, and the code I use often is VASP. > > Might I ask your help to recommend some more hand-on tutorials of > wannier90 interfacing with VASP? I know some examples of using > wannier90 on VASP official website, but still need more examples. > > Thank you. > > Best regards, > > Ming Yang > > _________ > > Department of Physics, > > National University of Singapore > _______________________________________________ > Wannier mailing list > Wannier at quantum-espresso.org > http://mailman.qe-forge.org/cgi-bin/mailman/listinfo/wannier From suresh2007pgp19 at gmail.com Sun Nov 29 03:09:19 2015 From: suresh2007pgp19 at gmail.com (Suresh A) Date: Sun, 29 Nov 2015 07:39:19 +0530 Subject: [Wannier] Computing Figure of merit: Reg Message-ID: Respected Experts/Friends, I am new one to wannier90. I have installed and ran transport examples for silicon and for CoSb3 to reproduce results successfully.In research papers they includes figure of merit (ZT) and electrical conductivity, Seebeck coefficients and thermal conductivity as a function of carrier concentrations. My question is 1) How to calculate figure of merit from Boltzwann? I am asking this because the code produce electrical conductivity, Seebeck coefficients, and Thermal conductivity as a function of chemical potential. 2) How to calculate electrical conductivity, Seebeck coefficients as a function of carrier concentration. If one has to do seperate calculation to compute figure of merit and tranport coefficients as a function of carrier concentration from obtained results then I request your help to know these calculations.I am eagerly waiting for the valuable reply. Thanks in advance With Regards, A.Suresh, Research Scholar, Madurai Kamaraj University, Madurai. -------------- next part -------------- An HTML attachment was scrubbed... URL: From genghuiyuan at hit.edu.cn Sun Nov 29 05:51:33 2015 From: genghuiyuan at hit.edu.cn (genghuiyuan) Date: Sun, 29 Nov 2015 12:51:33 +0800 Subject: [Wannier] =?utf-8?b?5Zue5aSNOiAgQ29tcHV0aW5nIEZpZ3VyZSBvZiBtZXJp?= =?utf-8?q?t=3A_Reg?= Message-ID: <565A844F.15EEEF.21170@hit.edu.cn> An HTML attachment was scrubbed... URL: From giovanni.pizzi at epfl.ch Sun Nov 29 17:28:16 2015 From: giovanni.pizzi at epfl.ch (Giovanni Pizzi) Date: Sun, 29 Nov 2015 16:28:16 +0000 Subject: [Wannier] Computing Figure of merit: Reg In-Reply-To: References: Message-ID: On 29 Nov 2015, at 03:09, Suresh A > wrote: Respected Experts/Friends, I am new one to wannier90. I have installed and ran transport examples for silicon and for CoSb3 to reproduce results successfully.In research papers they includes figure of merit (ZT) and electrical conductivity, Seebeck coefficients and thermal conductivity as a function of carrier concentrations. My question is 1) How to calculate figure of merit from Boltzwann? I am asking this because the code produce electrical conductivity, Seebeck coefficients, and Thermal conductivity as a function of chemical potential. As already pointed out, you need to calculate the lattice contribution to the thermal conductivity with some other code if you want to have realistic estimate of ZT. 2) How to calculate electrical conductivity, Seebeck coefficients as a function of carrier concentration. You need to use the values as a function of the chemical potential, and use the Density of States (also output [optionally] by BoltzWann, see the user guide) to relate the chemical potential with the doping and temperature you want to consider. The procedure is described at the end of the BoltzWann paper (Comp. Phys. Comm., 2014, 185, 422-429), see end of page 428 - beginning of 429. Giovanni If one has to do seperate calculation to compute figure of merit and tranport coefficients as a function of carrier concentration from obtained results then I request your help to know these calculations.I am eagerly waiting for the valuable reply. Thanks in advance With Regards, A.Suresh, Research Scholar, Madurai Kamaraj University, -- Giovanni Pizzi Post-doctoral Research Scientist EPFL STI PRN-MARVEL Room MED2 1326 Station 9 CH-1015 Lausanne (Switzerland) Phone: +41 21 69 31124 -------------- next part -------------- An HTML attachment was scrubbed... URL: