From pablo.villar at esrf.fr  Wed Jan  6 18:21:22 2016
From: pablo.villar at esrf.fr (Pablo Villar Arribi)
Date: Wed, 06 Jan 2016 18:21:22 +0100
Subject: [Wannier] =?utf-8?q?Any_criteria_for_selecting_the_inner/outer_en?=
 =?utf-8?q?ergy_windows=3F?=
Message-ID: <acc1b4ef8370992dce2ad9012352aafb@esrf.fr>

Dear Wannier90 users,

I am working with the code on some iron pnictides. I was not easy but 
now I am able to get real MLWFs for the iron
atoms in some of them (and also zero imaginary part in the real-space 
hamiltonian). However, I can see that both
the convergence and the final spreads strongly depend on the size of the 
inner/outer energy windows. What I have
tried is to disentangle the iron d-bands from the other ones present in 
the same energy range, trying to set the
inner window as big as possible and the outer one containing all the 
bands and features of interest. For some
reason I cannot set the inner energy window wider than 0.35-0.4 eV in 
some compounds, which seems very narrow to
me, since I want to get a reconstruction as close as possible to the DFT 
original one. In other cases I cannot
even reach convergence no matter how small is the size of the inner 
window.

My question is what is the best criteria to know which sizes for both 
energy windows provide a better reconstruction of the DFT electronic 
structure.

Thank you very much in advance.

Pablo


---------------------
Pablo Villar Arribi
PhD student at ESRF
Grenoble, France
--------------------


From liujiang86 at gmail.com  Fri Jan 15 13:10:35 2016
From: liujiang86 at gmail.com (liujiang86 at gmail.com)
Date: Fri, 15 Jan 2016 13:10:35 +0100
Subject: [Wannier] Fit the bandstructure to DFT's results under an exteral
	applied electric field
Message-ID: <2016011513103254439814@gmail.com>

Dear Wannier90 users, 

            I am working with the code on 2D materials under an normal exteral electric field.  I am wondering whether wannier90 can fit well the bandstructure to DFT's results under an exteral applied electric field?  Attempts were made, I got the following results (red: wannier fitting; green: dft results). Is it possible to remove the anomalous fluctuatation for band dispersion near the Fermi level? 





Sincerely yours,
Liujiang Zhou

Wannier mailing list
Wannier at quantum-espresso.org
http://mailman.qe-forge.org/cgi-bin/mailman/listinfo/wannier
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From halimazaari at gmail.com  Sun Jan 17 21:49:35 2016
From: halimazaari at gmail.com (Halima Zaari)
Date: Sun, 17 Jan 2016 20:49:35 +0000
Subject: [Wannier] transport properties
Message-ID: <CAAwk7s7arppHXGMCZmcyg6H6FhcXUZcZ9hhvYkoMO356k76uhw@mail.gmail.com>

Dear all,

I am having a problem with the input .win how i can create it; i want
to compute the transport properties of graphene monolayer following
the example 14 and 15 of Na_chain and carbone nanotube


specially these line:

begin projections

Na:sp-1

end projections

how i can modifie it o do my example

cordially

-- 
H.ZAARI

*PhD Student in laboratory of magnetism and physics of high energy (LMPHE)*
*Faculty of Sciences in Rabat - Morocco*
*Email: halimazaari at gmail.com <halimazaari at gmail.com>*
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From oarcelus at hotmail.com  Thu Jan 21 11:59:25 2016
From: oarcelus at hotmail.com (Oier Arcelus)
Date: Thu, 21 Jan 2016 11:59:25 +0100
Subject: [Wannier] Downfolding and transfer integrals
Message-ID: <DUB131-W23CCD8E8BAD1B4F74CA7B3DFC30@phx.gbl>

Hello Forum,

I want to calculate the magnetic exchange parameters of some very small clusters that I have relaxed. So I targeted my low energy bands of interests and extracted the MLWF out of them. I have the following questions.

1- If I express my GGA-type hamiltonian in the basis of my target wannier orbitals (If im not wrong, wannier90 already has a tag to do this) do the off diagonal elements express the values for the transfer integrals between my wannier functions?

2- To extract the J magnetic exchange interactions, do I need to apply the downfolding procedure to the subspace of pairs of wannier functions, so I can extract the effective hamiltonian that regards only to that pairs? If so, there is something that confuses me. As far as I understand, the downfolding procedure works to separate the high-energy degrees of freedom from the low-energy ones in which we are interested. However I only targeted low-energy bands so there are no high-energy degrees of freedom to be separated. Maybe I'm just writing non-sense I am not familiar with those concepts at all.

Cheers,

Oier.
 		 	   		  
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From ch-wang at outlook.com  Sun Jan 31 10:58:19 2016
From: ch-wang at outlook.com (chong wang)
Date: Sun, 31 Jan 2016 17:58:19 +0800
Subject: [Wannier] gauge problems in mmn file
Message-ID: <BLU437-SMTP21FFC0BEC564D694C16A4DE5DD0@phx.gbl>

Dear wannier users and developers:

I have been working on velocity matrix(berry connection of different bands) in band theory recently. Since wannier code does not output velocity matrix, I have been looking at the source code these days.

As you have probably known, calculating of berry connection suffers 'smooth gauge problem?. That is, since bloch wave functions can be multiplied by an arbitrary phase, one must obtain a smooth gauge for bloch wave functions to calculate finite difference.

I noticed that some source code directly used discrete versions of formula in MV90(Maximally localized generalized Wannier functions for composite energy bands), which requires ?mmn' matrix to be continuous in brillouin zone. Initial ?mmn? matrix is read from .mmn file. Does this mean in .mmn file gauge has already been fixed in some way?

Looking forward to your reply!

Best?

Chong Wang