[Pw_forum] Lowdin charge problem
lfhuang
lfhuang at theory.issp.ac.cn
Sat Sep 5 16:21:35 CEST 2009
Dear L. D. Ding:
In my opinion, this kind of thing also can be understood from group theory for quantum mechanics: the "carrier space" of the eigen-function of bulk materials are not consistent with the one of the atomic wavefunctions, although both of them form orthogonal and complete basis sets. So the projection operation between the two spaces will miss some information. To some extent, this is the same as Duy Le's comment.
Best Regards
L. F. Huang
Institute of Solid State Physics of China
> 1. Lowdin charge problem (loc duong ding)
> 2. Re: Lowdin charge problem (Duy Le)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Fri, 4 Sep 2009 18:59:30 -0700 (PDT)
> From: loc duong ding
> Subject: [Pw_forum] Lowdin charge problem
> To: PWscf forum
> Message-ID:
> Content-Type: text/plain; charset=iso-8859-1
>
> Dear QE users,
>
> I try to analysis the atomic charge. I found that Lowdin charge analysis can be implemeted by QE. I dod a test with NO2. I get the the result as following:
>
> Lowdin Charges:
> ???? Atom #?? 1: total charge =?? 4.5377, s =? 1.2595, p =? 3.2782,
> ???????????????? spin up????? =?? 2.4718, s =? 0.7016, p =? 1.7701,
> ???????????????? spin down??? =?? 2.0659, s =? 0.5578, p =? 1.5081,
> ???????????????? polarization =?? 0.4058, s =? 0.1438, p =? 0.2620,
> ???? Atom #?? 2: total charge =?? 6.1075, s =? 1.7256, p =? 4.3818,
> ???????????????? spin up????? =?? 3.1926, s =? 0.8642, p =? 2.3284,
> ???????????????? spin down??? =?? 2.9149, s =? 0.8614, p =? 2.0534,
> ???????????????? polarization =?? 0.2777, s =? 0.0027, p =? 0.2749,
> ???? Atom #?? 3: total charge =?? 6.1113, s =? 1.7254, p =? 4.3859,
> ???????????????? spin up????? =?? 3.1939, s =? 0.8641, p =? 2.3298,
> ???????????????? spin down??? =?? 2.9174, s =? 0.8613, p =? 2.0561,
> ???????????????? polarization =?? 0.2765, s =? 0.0028, p =? 0.2737,
>
> The strange thing is that the total charge of all atom is ~16.7 instead of 17 in NO2 molecules.
>
> Can you give me some instructions or explanation to fix this problem?
>
> I great appreciate your help.
>
> Sincerely,?-----------------------------------------------
> Loc Duong Dinh
> Ms-Ph.D Student
> Sungkyunkwan Advanced Institute of Nanotechnology,
> Sungkyunkwan University,
> Suwon, 440-746, Korea
> Email: mambom1902 at yahoo.com, ddloc at skku.edu
>
>
>
>
>
> ------------------------------
>
> Message: 2
> Date: Fri, 4 Sep 2009 22:31:06 -0400
> From: Duy Le
> Subject: Re: [Pw_forum] Lowdin charge problem
> To: PWSCF Forum
> Message-ID:
>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Hi,I don't think you can get 17e for not only Lowdin charge but also others.
> This estimated charge does not follow the sum rule. I believe the "error"
> comes from the delocolized charge which can not be well estimated or taken
> in to account.
>
> D.
>
> On Fri, Sep 4, 2009 at 9:59 PM, loc duong ding wrote:
>
> > Dear QE users,
> >
> > I try to analysis the atomic charge. I found that Lowdin charge analysis
> > can be implemeted by QE. I dod a test with NO2. I get the the result as
> > following:
> >
> > Lowdin Charges:
> > Atom # 1: total charge = 4.5377, s = 1.2595, p = 3.2782,
> > spin up = 2.4718, s = 0.7016, p = 1.7701,
> > spin down = 2.0659, s = 0.5578, p = 1.5081,
> > polarization = 0.4058, s = 0.1438, p = 0.2620,
> > Atom # 2: total charge = 6.1075, s = 1.7256, p = 4.3818,
> > spin up = 3.1926, s = 0.8642, p = 2.3284,
> > spin down = 2.9149, s = 0.8614, p = 2.0534,
> > polarization = 0.2777, s = 0.0027, p = 0.2749,
> > Atom # 3: total charge = 6.1113, s = 1.7254, p = 4.3859,
> > spin up = 3.1939, s = 0.8641, p = 2.3298,
> > spin down = 2.9174, s = 0.8613, p = 2.0561,
> > polarization = 0.2765, s = 0.0028, p = 0.2737,
> >
> > The strange thing is that the total charge of all atom is ~16.7 instead of
> > 17 in NO2 molecules.
> >
> > Can you give me some instructions or explanation to fix this problem?
> >
> > I great appreciate your help.
> >
> > Sincerely, -----------------------------------------------
> > Loc Duong Dinh
> > Ms-Ph.D Student
> > Sungkyunkwan Advanced Institute of Nanotechnology,
> > Sungkyunkwan University,
> > Suwon, 440-746, Korea
> > Email: mambom1902 at yahoo.com, ddloc at skku.edu
> >
> >
> >
> > _______________________________________________
> > Pw_forum mailing list
> > Pw_forum at pwscf.org
> > http://www.democritos.it/mailman/listinfo/pw_forum
> >
>
>
>
> --
> --------------------------------------------------
> Duy Le
> PhD Student
> Department of Physics
> University of Central Florida.
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------
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L.F.Huang(黄良锋) ph.D candidate
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