[Pw_forum] a question for projwfc.x

[vega lew]

Dear sir,

I'm very grateful to your help and time.

Now, my understanding about this issue improved greatly with your help.
best wishes,

vega


On Mon, Jan 19, 2009 at 11:57 PM, Axel Kohlmeyer <
akohlmey at cmm.chem.upenn.edu> wrote:

> On Mon, 19 Jan 2009, vega lew wrote:
>
> VL> Dear all,
> VL>
> VL> in input file description of projwfc.x, it's said that the code could
> VL> identify the different contribution of Px, Py and Pz, or D sub
> orbitals.
> VL>
> VL> I wonder if there is a literature describe the algorithm and the
>  physical
> VL> meaning in detail.
>
> have a look into a text book on linear algebra and look up projections.
>
> pw.x uses a plane wave basis set, projwfc.x projects the wavefunction
> expressed in the plane wave basis upon the atomic pseudowavefunctions
> stored in the pseudopotentials (which is not perfect, btw. some part
> of the wavefunction will remain unassigned, since you are using an
> incomplete basis). the physical meaning is that one tries to attribute
> the contributions from the individual atoms to the individual states.
>
> the process is similar to, say, expanding an irrational function
> through a polynomial and then try to describe the original function
> through the contributions of the individual "power of x" coefficients.
>
> cheers,
>  axel.
>
> VL>
> VL> thank you for reading
> VL>
> VL> vega
> VL>
>
> --
> =======================================================================
> Axel Kohlmeyer   akohlmey at cmm.chem.upenn.edu   http://www.cmm.upenn.edu
>   Center for Molecular Modeling   --   University of Pennsylvania
> Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323
> tel: 1-215-898-1582,  fax: 1-215-573-6233,  office-tel: 1-215-898-5425
> =======================================================================
> If you make something idiot-proof, the universe creates a better idiot.
>



-- 
==================================================================================
Vega Lew ( weijia liu)
PH.D Candidate in Chemical Engineering
State Key Laboratory of Materials-oriented Chemical Engineering
College of Chemistry and Chemical Engineering
Nanjing University of Technology, 210009, Nanjing, Jiangsu, China
******************************************************************************************************************
Email: vegalew at gmail.com
Office: Room A705, Technical Innovation Building, Xinmofan Road 5#, Nanjing,
Jiangsu, China
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