[Pw_forum] ibrav=12

[Carlo Nervi]

Dear Paul,
commenting your note, and as a chemist, I've been confused
by the convenction used in quantum espresso.
I'm using a, b, c, alpha, beta and gamma, but not always
I've been able to directly translate the content of cif
files into QE input...
Here is an example about monoclinic input:
http://www.democritos.it/pipermail/pw_forum/2010-February/015993.html

I had to switch (b, c) in the cell and (y, z) in the data....

Finally i decided to use only triclinic for all input
files, regardless of the real ibrav...

Just my 2c...

Carlo

--
------------------------------------------------------
Carlo Nervi carlo.nervi at unito.it Tel:+39 011 6707507/8
Fax: +39 011 6707855 - Dipartimento di Chimica IFM
via P. Giuria 7, 10125 Torino, Italy
http://lem.ch.unito.it/

>
>
> ------------------ Messaggio originale -------------------
> Oggetto: Re: [Pw_forum] ibrav=12
> Da:      "W2AGZ" <w2agz at w2agz.com>
> Data:    Ven, 18 Febbraio 2011, 8:43 pm
> A:       "'PWSCF Forum'" <pw_forum at pwscf.org>
> ----------------------------------------------------------
>
> Thanks, Eyvaz.  The space group I’m interested in is
> P21/c  (14).  8 atoms per unit cell, 24 IRs.  If you need
> a beta tester, just ask.  -Paul
>
>
>
> From: pw_forum-bounces at pwscf.org
> [mailto:pw_forum-bounces at pwscf.org] On Behalf Of Eyvaz
> Isaev
> Sent: Friday, February 18, 2011 9:05 AM
> To: PWSCF Forum
> Subject: Re: [Pw_forum] ibrav=12
>
>
>
> Dear Paul,
>
> In fact, I am working on this problem in order to support
> in PlotPhon almost all lattice types. I will let you know
> soon, hopefully.
>
>
> Best regards,
> Eyvaz.
>
> -------------------------------------------------------------------
> Prof. Eyvaz Isaev,
> Department of Physics, Chemistry, and Biology (IFM),
> Linkoping University, Sweden
> Theoretical Physics Department, Moscow State Institute of
> Steel & Alloys, Russia,
> isaev at ifm.liu.se, eyvaz_isaev at yahoo.com
>
>
>
>
>
>   _____
>
> From: W2AGZ <w2agz at w2agz.com>
> To: pw_forum at pwscf.org
> Sent: Fri, February 18, 2011 10:06:08 AM
> Subject: [Pw_forum] ibrav=12
>
> To All (especially Eyvaz):
>
>
>
> I would like to create a file for PlotPhon/Include to
> support general monoclinic structures.  Below is the
> Include file for orthorhombic as an example “kick
> off:�
>
>
>
> # Simple Orthorhombic lattice (X=b/a, Y=c/a)
>
>   1.0  0.0       0
>
>   0.0  XX        0
>
>   0.0  0.0       YY
>
> # With respect to basis vectors
>
> 1   0.00000  0.00000   0.50000    Z
>
> 50  0.00000  0.00000   0.00000    G
>
> 50  0.500000 0.00000   0.00000    X
>
> 50  0.500000 0.50000   0.00000    S
>
> 50  0.000000 0.50000   0.00000    Y
>
> 50  0.000000 0.00000   0.00000    G
>
> 50  0.500000 0.50000   0.50000    R
>
>
>
> Now, the “popular� cell convention for
monoclinic
> structures is either “b-axis-unique,� or
> “c-axis-unique.�  PWgui and PWscf prefer the
latter,
> but that’s OK, since it’s a simple transformation, as
> least in direct space, between the two.  But, what is the
> appropiate “include� for ibrav=12 “c-axis
unique?�
>  I’ve been to “BILBOA,� and the
> Bouchaert-Smoluchowski-Wigner path I want is
> gamma-a-u-e-z-lambda-gamma for both electrons and phonons.
>  Incidentally, when I was a graduate student, the legend
> was that the BSW notation was invented by physicists to
> purposely confuse chemists.  So, please tell me how to
> construct the appropriate “scripts/lines� and
> “include� files accordingly.
>
>
>
> Grazi, Paul Grant
>
> IBM Research Staff Member Emeritus
>
> www.w2agz.com
>
>
>
> Addenda...I include the following at the risk of angering
> Santo Paolo who may excommunicate me from the forum on the
> basis of “topic out of bounds.� “Mea
culpa...dominus
> noster...�  Therefore I apologize for this
posting and
> to those for whom English is not their native language,
> especially Americans, Australians, Kiwis, Irish, Scots,
> Welsh, Cornish, Indians and particularly Quebecois
> (British Columbians excepted).
>
>
>
> 2011 is the 100th anniversary of the discovery of
> superconductivity and the 25th of above liquid nitrogen in
> copper oxide perovskites.  I will be giving one of the
> plenary talks at the upcoming APS March Meeting in
> Dallas...go here
> <http://meetings.aps.org/Meeting/MAR11/APS_epitome>  for
> the epitome.  And later a reprise at the MRS April Meeting
> in San Francisco.  But, in addition, I will also present a
> contributed talk at each meeting on “proxy� CuO
> structures based entirely on Quantum Espresso
> resources...go here
> <http://meetings.aps.org/Meeting/MAR11/Event/139995>  to
> see.
>
>
>
> I would love to see and meet members of the QE community
> at each event...and offer a “real espresso�
beverage.
>  Look for me outside any of the superconductivity
> sessions, or inquire in the press room.  I’m reasonably
> identifiable...an old guy with long white hair and beard.
>  Hmm...well...maybe not that unique!
>
>
>
>
>
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