While there is some rationale to changing the angles to 90, this is in general not appropriate.
Rather than doing this I suggest working through the examples in the Wien2k documentation. There are also examples in the Lecture notes on the web page. This will teach you a lot. On Thu, Apr 23, 2015 at 10:02 AM, delamora <[email protected]> wrote: > The simplest perivskite is > a=b=c > alpha=beta=gamma=90 > A: 1/2,1/2,1/2 > B: 0,0,0 > O: 1/2,0,0 > 0,1/2,0 > 0,0,1/2 > space group 221 > so, if you have alpha=89.999 you can adjust to 90. > Now, if you have alpha=89.9 you can adjust to 90 for learning purposes, > the calculation will be quite fast, but the final calculation you should > use 89.9 and the pbnm group that has lower symmetry > Pablo > > ________________________________________ > De: [email protected] < > [email protected]> en nombre de Víctor Luaña Cabal < > [email protected]> > Enviado: jueves, 23 de abril de 2015 07:54 a. m. > Para: A Mailing list for WIEN2k users > Cc: Victor Luaña > Asunto: Re: [Wien] (no subject) > > On Thu, Apr 23, 2015 at 05:56:00PM +0530, Shakeel Khandy wrote: > > I m a beginner and i want to study a compound of ABO3 type pervoskite > with > > space group *pbnm*.I have got confused with the atomic positions of > > *pbnm *spacegroup. > > Although the experimental atomic positions are in my hand,but the problem > > lies in the negative atomic positions given by experimental data. Is > there > > any other method to have the required atomic positions. > > Shakeel, > > 1) The crystallographic description of coordinates assumes periodicity. > So x=-0.12 is identical to 1+x=1-0.12. Any crystallographer is trained > to do the operation quickly and the easy way is thinking > > 1 = 0.999999999(10) > --------- as mant 9's as it is needed > > 2) ¿Don't have a professor to traing you? ¿Don't have books on > crystallography available? > > 3) Assuming the answers are NO in both cases let me recommend > you some materials appropriate to the level of your question > > a) My own slides on the subject > > <http://azufre.quimica.uniovi.es/DetEst/> > > Sorry by the spanish. Use google translate as you need. > > b) An excellent and recent manual by italian crystallographers: > > C. Giacovazzo, Ed. Fundamentals of crystallography, IUCr & Oxford Univ > Press > IUCR: 0198555784, 1992 > > There is a new edition, but I don't have it al hand. > > 4) This type of question should be solved by your prof./teacher > > Good luck, > Dr. Víctor Luaña > -- > . . DEEP THOUGHT in D. Adams; Hitchhikers Guide to the Galaxy: > / `' \ "I think the problem, to be quite honest with you, > /(o)(o)\ is that you have never actually known what the question is." > /`. \/ .'\ > / '`'` \ "Lo mediocre es peor que lo bueno, pero también es peor > | \'`'`/ | que lo malo, porque la mediocridad no es un grado, es una > | |'`'`| | actitud" > \/`'`'`'\/ -- Jorge Wasenberg, 2015 > ===(((==)))==================================+========================= > ! Dr.Víctor Luaña, in silico chemist & prof. ! Mediocre is worse than > ! Departamento de Química Física y Analítica ! good, but it is also > ! Universidad de Oviedo, 33006-Oviedo, Spain ! worse than bad, because > ! e-mail: [email protected] ! mediocrity is not a grade, > ! phone: +34-985-103491 fax: +34-985-103125 ! it is an attitude > +--------------------------------------------+ > GroupPage : http://azufre.quimica.uniovi.es/ > (being reworked) > _______________________________________________ > Wien mailing list > [email protected] > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien > SEARCH the MAILING-LIST at: > http://www.mail-archive.com/[email protected]/index.html > _______________________________________________ > Wien mailing list > [email protected] > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien > SEARCH the MAILING-LIST at: > http://www.mail-archive.com/[email protected]/index.html > -- Professor Laurence Marks Department of Materials Science and Engineering Northwestern University www.numis.northwestern.edu Corrosion in 4D: MURI4D.numis.northwestern.edu Co-Editor, Acta Cryst A "Research is to see what everybody else has seen, and to think what nobody else has thought" Albert Szent-Gyorgi
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