[Pw_forum] wavefunction coefficients

[Karoly Nemeth]

Thank you Gabriele! Since most of the time the *.wfc* are split among a 
few files, a utility that uses as input only the number of processors, 
nspin, and perhaps the number of basis functions could be useful. If the 
wfc files would be in hdf5 format it would be probably easier to figure 
out all their structure, but since this is not the case, a utility program 
could be quite useful for this purpose.

Karoly

***********************************************************************
Karoly Nemeth, Ph.D.
Argonne National Laboratory
9700 S. Cass Ave. Argonne, IL 60439.
Advanced Photon Source
Accelerator Physics and Operations Group
Building 401, Room B2200
Tel. 630-252-5813
Fax: 630-252-4732
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> Message: 3
> Date: Thu, 22 Jan 2009 09:54:17 +0100
> From: Gabriele Sclauzero <sclauzer at sissa.it>
> Subject: Re: [Pw_forum] wavefunction coefficients
> To: PWSCF Forum <pw_forum at pwscf.org>
> Message-ID: <49783439.40104 at sissa.it>
> Content-Type: text/plain; charset=us-ascii; format=flowed
>
> Hi,
>
>    of course Paolo and Axel could help you much more than me on this issue, but inthe
> meanwhile:
>
> Karoly Nemeth wrote:
>> Hi,
>>
>> I would like to obtain the wavefunction coefficients u(i,k,G), where "i"
>> is the band-index, "k" is the k-space vector used in the discretization of
>> the Brillouin-zone in a PW calculation and "G" is the plane-wave basis
>> function's wave-vector (assuming a complex form as exp[i(k+G)r] ).
>
> I think that the quantities you are interested in are store in the variable "evc" of the
> pw program (but only in certains parts of the program and only for one k-point at a time;
>  the wavefunctions for all the k-points are stored on the .wfc files).
>
>>
>> Is there any utility program that is independent from the rest of PWSCF
>> and would provide some sort of tabulation on u(i,k,G) as a function
>> of i,k and G , for a parallel calculation? Perhaps a quick quide to the
>> format of this information in the *.wfc* files written by a parallel run?
>
> Be careful that in parallel runs the G vectors (i.e. plane waves) are split across
> processor, so that each processor may be working only with a slab of the full grid.
> The option wfc_collect=.TRUE. collects all wavefunctions on a single file after the
> parallel run (maybe it can help you understand how to gather all the coefficients).
>
> GS
>
> PS: The forum community would be grateful if you specify your affiliation... thanks.
>
>>
>> I would appreciate any hint that could save me some time from going
>> through the source code for this info.
>> Thanks a lot in advance:
>>
>> Karoly
>>