From nicolas.lorente at cin2.es Fri Nov 11 15:35:34 2011 From: nicolas.lorente at cin2.es (Nicolas Lorente) Date: Fri, 11 Nov 2011 15:35:34 +0100 Subject: [Wannier] Fixed centers? Message-ID: <4EBD32B6.3010003@cin2.es> Hi, is there anyway of fixing the Wannier centers so they don't move during the minimization of the spread? This can be useful to identify symmetries or to assign some physical meaning to certain Wannier functions (we are interested in "defining" an impurity, and sometimes the Wannier functions move away from the impurity). Thanks, Nicol?s -- Nicol?s Lorente Centro de Investigaci?n en Nanociencia y Nanotecnolog?a Campus de la UAB E-08193 Bellaterra Tel. (+34) 935868410 -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: nicolas_lorente.vcf Type: text/x-vcard Size: 179 bytes Desc: not available URL: From poilvert at mit.edu Fri Nov 11 17:03:58 2011 From: poilvert at mit.edu (nicolas poilvert) Date: Fri, 11 Nov 2011 11:03:58 -0500 Subject: [Wannier] Fixed centers? In-Reply-To: <4EBD32B6.3010003@cin2.es> References: <4EBD32B6.3010003@cin2.es> Message-ID: Dear Nicolas, I am unsure whether you can "force" the wannier centres to be the ones you give, but at least you can "guide" the wannierisation operation by defining the "guiding_centres" keyword to be ".true." in the master Wannier90 input. But maybe you already did that ! Nicolas On Fri, Nov 11, 2011 at 9:35 AM, Nicolas Lorente wrote: > Hi, > > is there anyway of fixing the Wannier centers so they don't move during > the minimization of the spread? > > This can be useful to identify symmetries or to assign some physical > meaning to certain Wannier functions (we > are interested in "defining" an impurity, and sometimes the Wannier > functions move away from the impurity). > > Thanks, > > Nicol?s > > -- > Nicol?s Lorente > Centro de Investigaci?n en Nanociencia y Nanotecnolog?a > Campus de la UAB > E-08193 Bellaterra > Tel. (+34) 935868410 > > > _______________________________________________ > Wannier mailing list > Wannier at quantum-espresso.org > http://www.democritos.it/mailman/listinfo/wannier > > -- Nicolas POILVERT, PhD Post-doctoral Fellow Rowland Institute at Harvard -------------- next part -------------- An HTML attachment was scrubbed... URL: From nicolas.lorente at cin2.es Fri Nov 11 17:16:50 2011 From: nicolas.lorente at cin2.es (Nicolas Lorente) Date: Fri, 11 Nov 2011 17:16:50 +0100 Subject: [Wannier] Fixed centers? In-Reply-To: References: <4EBD32B6.3010003@cin2.es> Message-ID: <4EBD4A72.2010909@cin2.es> On 11/11/11 17:03, nicolas poilvert wrote: > Dear Nicolas, > > I am unsure whether you can "force" the wannier centres > to be the ones you give, but at least you can "guide" the > wannierisation operation by defining the "guiding_centres" > keyword to be ".true." in the master Wannier90 input. > > But maybe you already did that ! > > Nicolas > > Thanks, yes, we tried it. Actually the guiding_centers option solves some issues as Jonathan Yates points out in this list (and also some e-mail he sent us), but we have seen no effect on the position of the wannier centers, it is rather in the phase of the wannier functions (right? I understood you avoid numerical jumps of 2 pi in the phase). I don't even know if it is meaningless to try to fix the centers. I guess no... Thanks for your help, Nicol?s -- Nicol?s Lorente Centro de Investigaci?n en Nanociencia y Nanotecnolog?a Campus de la UAB E-08193 Bellaterra Tel. (+34) 935868410 -------------- next part -------------- A non-text attachment was scrubbed... Name: nicolas_lorente.vcf Type: text/x-vcard Size: 179 bytes Desc: not available URL: From nicolas.lorente at cin2.es Sat Nov 12 14:31:44 2011 From: nicolas.lorente at cin2.es (Nicolas Lorente) Date: Sat, 12 Nov 2011 14:31:44 +0100 Subject: [Wannier] Fixed centers? In-Reply-To: <4EBDA6E1.3060201@civet.berkeley.edu> References: <4EBD32B6.3010003@cin2.es> <4EBDA6E1.3060201@civet.berkeley.edu> Message-ID: <4EBE7540.9050708@cin2.es> On 11/11/11 23:51, Sinisa Coh wrote: > Nicolas Lorente wrote: >> Hi, >> >> is there anyway of fixing the Wannier centers so they don't move >> during the minimization of the spread? >> >> This can be useful to identify symmetries or to assign some physical >> meaning to certain Wannier functions (we >> are interested in "defining" an impurity, and sometimes the Wannier >> functions move away from the impurity). > > Dear Nicolas, > > Could you try adding to minimization functional a penalty for Wannier > center being away from where you want it to be and then try to > minimize that functional? > > This would involve some patching of the Wannier code I guess, but it > doesn't seem that hard to do. > > One problem I see right away is that then you would need to pick an > arbitrary constant in front of the penalty and that will introduce new > parameter in the problem. Therefore your final Wannier functions will > not be unique (unlike max-loc functions which are, more or less). > > Best, > Sinisa > OK, I guess you are right and this is the way to go. But, wouldn't it be easier just to remove the Wannier center from the list of parameters to update when minimizing the spread? I have not looked into wannier90, I don't know how tough it is to effect any changes. Thanks, Nicol?s -- Nicol?s Lorente Centro de Investigaci?n en Nanociencia y Nanotecnolog?a Campus de la UAB E-08193 Bellaterra Tel. (+34) 935868410 -------------- next part -------------- A non-text attachment was scrubbed... Name: nicolas_lorente.vcf Type: text/x-vcard Size: 179 bytes Desc: not available URL: From njuwangda at gmail.com Mon Nov 14 08:15:03 2011 From: njuwangda at gmail.com (da wang) Date: Mon, 14 Nov 2011 15:15:03 +0800 Subject: [Wannier] How to get real hoppings in seedname_hr.dat? Message-ID: Dears, I am using wannier90 to get a tight-binding model. As the user's guide, hoppings are listed in file seedname_hr.dat. I did that, but I always obtain hoppings with both real and imaginary part. Is there any method to get hoppings with only real part? Thanks. yours, Da Wang, Nanjing Univ., China -------------- next part -------------- An HTML attachment was scrubbed... URL: From njuwangda at gmail.com Thu Nov 17 06:21:06 2011 From: njuwangda at gmail.com (da wang) Date: Thu, 17 Nov 2011 13:21:06 +0800 Subject: [Wannier] projection for Kagome lattice Message-ID: Dears, As we know, for the graphene-type lattice, sp2 hybridyzation orbital is a proper candidates for the wannier orbital, that is, we should set sp2 for the projection block. Now I am treating Kagome-type lattice, when I put all possible orbitals (s,p,d) in, I cannot get real hoppings. I think maybe my input projection has some problem (Both the initial guess orbital and center position). So which kind of input projections is proper for a Kagome-type lattice? Thanks, Da Wang Nanjing Univ. -------------- next part -------------- An HTML attachment was scrubbed... URL: