[Pw_forum] URGENT

[Axel Kohlmeyer]

dear amit,

please note, that a subject line of 'URGENT' and using
many question marks in your mail formatting, will only
help to not been taken seriously. developers/hackers tend
to have sometimes unusual ways of giving an email
credibility (or not). please have a look at:

http://www.catb.org/~esr/faqs/smart-questions.html

which explains a lot of it and how you can and should
try to deal with it (note that this page contains some irony!).


On 10/27/06, Amit Kumar <amit76.india at gmail.com> wrote:
>   Dear users
> I could not understand how one can set atomic positions in any calculations.
> In perticular if I know the space group PNMA62 and fractional coordinate of
> sample LaMnO3
> molecule (Everywhere position of La Mn O1 O2 are given How will I find out
> atomic position of
>
> 3rd Oxygen using symetry??? Any reference for example??? ). Is anybody aware
> of how coordinates in premittive cell can be
> generated for perticular space group and frictional coordinates. How will I
> make a supercell of 4 formula unit for Orthorhombic structure????
>
> Is there any good reference on formation of supercell for non cubic
> crystal?????

you may want to look at the material posted at:
http://www.vlab.msi.umn.edu/events/lecture.shtml
and especially.
http://www.vlab.msi.umn.edu/events/download/tutorial_wyckoff.pdf

the people at VLAB have done a great job in re-editing
the material of the recent tutorial.

> Why the manual is not as clear as ABINIT in PWSCF????

because there are a _lot_ of people who ask questions like
you do, but very _few_ do submit a text to be included into
the manual, once they have found out how it works and how
it should be explained to a new/inexperienced/regular/clueless user.

unlike the common perception, writing useful documentation
actually does _not_ require a lot of experience, but simply some
dedication and time investment. once done changes or additions
can be mailed to pwscf at pwscf.org, or the mailing list here or
added to the wiki on www.quantum-espresso.org and then
experienced people will review it (which takes only fraction of
their time compared to having to write it from scratch and thus
gives them more time to help you with the more tricky problems
and improve the codes).

note, that like in all other community driven projects, _your_
contribution is the way of how you 'pay back' for getting all the
nice code, material, and support for free to be used in your research.

> Thanks in
> anticipations.
> With best regards
> Amit

thanks in anticipation of your contribution ;-),
   axel.

-- 
=======================================================================
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.