[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [sdpd] Re: Peak missing!

I think that your problem is in oxygen position. It should be 1/2 1/2 0.

Another typical error.

Measure two times before you cut (a Czech proverb ) ...


Best regards

Radovan

higorfav a écrit :
> The tetragonal space group is the P4mm.
> The coordenates and the system used was BaTiO3 cubic phase. (Pm-3m)
> 
> atom  x    y    z
> Ba    0    0    0
> Ti    0.5  0.5  0.5  
> O     0.5  0    0
> 
> Thanks for the help.
> Higor.
> 
> 
> 
> --- In sdpd...@yahoogroups.com, Radovan Cerny <Radovan.Cerny...@...> wrote:
> 
>>The problem you had was the wrong choice of the origin with respect to 
>>the numerical values of the atomic coordinates you had. That's a
> 
> typical 
> 
>>error in the case of space groups which are tabulated with two
> 
> different 
> 
>>origins.
>>That's not the case of Higor. His space group is Pm-3m.
>>What are the atoms and atomic coordinates you have?
>>
>>Radovan
>>
>>Lujun...@EKM a écrit :
>>
>>>Hi, Higor:
>>>
>>>i hope i have understood your situation...
>>>i came across the similar problem. Fortunately, Prof. Gottschalk
> 
> told me the right way. Please see the Step 1 in the link for details
> http://www.physik.uni-augsburg.de/~lujun/.
> 
>>>Faithfully
>>>Jun Lu
>>>----------
>>>Lst. Prof. Lijie Qiao
>>>Department of Materials Physics and Chemistry
>>>University of Science and Technology Beijing
>>>100083 Beijing
>>>P.R. China
>>>http://www.instrument.com.cn/ilog/handsomeland/
>>>
>>>Lst. Prof. Loidl and Lunkenheimer
>>>Experimental Physics V
>>>Center for Electronic Correlations and Magnetism (EKM)
>>>University of Augsburg
>>>Universitaetsstr. 2
>>>86159 Augsburg
>>>Germany
>>>http://www.physik.uni-augsburg.de/exp5
>>> 
>>>  ----- Original Message ----- 
>>>  From: higorfav 
>>>  To: sdpd...@yahoogroups.com 
>>>  Sent: Wednesday, October 22, 2008 11:19 AM
>>>  Subject: [sdpd] Peak missing!
>>>
>>>
>>>  Dear all,
>>>  I tried to refine a spectra that teorically should be cubic, but
> 
> whem
> 
>>>  I started the refinement just one peak (111) is missing on teorical
>>>  fitting, but the phase matchs with the experimental peak.
>>>  Trying tetragonal symmetry, all peaks agree and refinement goes
> 
> well.
> 
>>>  I tried to change the origin of the system without result.
>>>  The question is:
>>>  Is there something to do in order to fit that missing peak or I have
>>>  to assume that the symmetry is tretagonal? Does anybody have
> 
> some ideas?
> 
>>>  Thanks in avance.
>>>  Higor.
>>>
>>>
>>>
>>>   
>>>
>>>[Non-text portions of this message have been removed]
>>>
>>>
>>>------------------------------------
>>>
>>>Yahoo! Groups Links
>>>
>>>
>>>
>>
>>
>>-- 
>>Radovan Cerny
>>Laboratoire de Cristallographie
>>24, quai Ernest-Ansermet
>>CH-1211 Geneva 4, Switzerland
>>Phone  : [+[41] 22] 37 964 50, FAX : [+[41] 22] 37 961 08
>>mailto : Radovan.Cerny...@...
>>URL    : http://www.unige.ch/sciences/crystal/cerny/rcerny.htm
>>
> 
> 
> 
> 
> ------------------------------------
> 
> Yahoo! Groups Links
> 
> 
> 


-- 
Radovan Cerny
Laboratoire de Cristallographie
24, quai Ernest-Ansermet
CH-1211 Geneva 4, Switzerland
Phone  : [+[41] 22] 37 964 50, FAX : [+[41] 22] 37 961 08
mailto : Radovan.Cerny...@cryst.unige.ch
URL    : http://www.unige.ch/sciences/crystal/cerny/rcerny.htm

------------------------------------

Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/sdpd/

<*> Your email settings:
    Individual Email | Traditional

<*> To change settings online go to:
    http://groups.yahoo.com/group/sdpd/join
    (Yahoo! ID required)

<*> To change settings via email:
    mailto:sdpd-digest...@yahoogroups.com 
    mailto:sdpd-fullfeatured...@yahoogroups.com

<*> To unsubscribe from this group, send an email to:
    sdpd-unsubscribe...@yahoogroups.com

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/