If there could be something "subtle" going on with the control file - is it
possible to get the data and GSAS, Fullprof, and DBWS control files
on a web or ftp site for general perusal?
Lachlan.
>I pretty sure this is not a problem with space group settings, bacause:
>a) I have descripbed the structure in various space groups in both GSAS and
>DBWS/Fullprof and the difference is always the same
>b) the problem is in one single peak only
>c) I have imported the GSAS .EXP-file into Cerius2 to draw the structure,
>and it appears just as I intended it to.
>
>Regards
>Magnus
>
>At 11:53 05.01.01 +0000, you wrote:
>>
>>> Doing Rietveld refinement with GSAS, I get close to zero calculated
>>> intensity in the 110 peak. The rest of the pattern fits nicely. I have
>>> tried to set POLA to diffent values between 0 and 1 (usually I lock it at
>>> 0.98), and I have also tried the three possible settings of IPOL. None of
>>> this has any significant influence on the calculated intensity of 110.
>>>
>>> If I insert my refined structure model into DBWS, I immediately get
>>> sensible intensity in 110. The same happened when a colleague tried it in
>>> Fullprof. The calculated structure factor for the peak is similar in GSAS
>>> and DBWS.
>>>
>>> Does anybody have a idea of what I can be doing wrong? Or can it be a
>>> problem with GSAS? I'm currently using the Linux version, but I have also
>>> tried older UNIX versions.
>>
>>The main occassions I have encountered this type of behaviour
>>(besides errors in structure input) is when different
>>default settings of the spacegroup are assumed by different
>>Rietveld programs.
>>Might this mean the structure has to be transformed into a
>>different spacegroup setting for which GSAS is the default?
>>
>>Inserting the cubic silicon metal co-ordinates directly
>>from the ICSD can cause initial mayhem with various
>>Rietvelds due to this.
>>
>>Lachlan.
>>
>>
>>--
>>Lachlan M. D. Cranswick
>>
>>Collaborative Computational Project No 14 (CCP14)
>> for Single Crystal and Powder Diffraction
>>Daresbury Laboratory, Warrington, WA4 4AD U.K
>>Tel: +44-1925-603703 Fax: +44-1925-603124
>>E-mail: [EMAIL PROTECTED] Ext: 3703 Room C14
>> http://www.ccp14.ac.uk
>>
>>
>>
>
>
Lachlan M. D. Cranswick
Collaborative Computational Project No 14 (CCP14)
for Single Crystal and Powder Diffraction
Daresbury Laboratory, Warrington, WA4 4AD U.K
Tel: +44-1925-603703 Fax: +44-1925-603124
E-mail: [EMAIL PROTECTED] Ext: 3703 Room C14
http://www.ccp14.ac.uk
