RE: 答复: Le bail and rietveld method

2016-06-15 Thread davide levy 
Dear Jin, 
as I understand, you made leBail and Rietveld refinement on the same data. The 
difference in the cell can due to the fact that with Rietveld method the 
intensities of the peaks are not well determinate so the cell is different in 
order to compensate the intensity difference. 
suggestion: keep the LeBail cell for the Rietveld refinement and then refine 
the structure  without refine the cell  and  profile parameters. After refine 
the cell and you should obtain the same result

Bests 

Davide 

 

From: rietveld_l-requ...@ill.fr [mailto:rietveld_l-requ...@ill.fr] On Behalf Of 
Payzant, E. Andrew
Sent: Wednesday, June 15, 2016 6:25 AM
To: rietveld_l@ill.fr; Peng, Jin 
Subject: Re: 答复: Le bail and rietveld method

 

Probably the sample height has shifted due to thermal contraction. Not likely a 
zero shift. 

 

Andrew

 

  _  


From: Peng, Jin mailto:jpe...@tulane.edu> >
Date: June 14, 2016 at 7:55:29 PM EDT
To: rietveld_l@ill.fr <mailto:rietveld_l@ill.fr>  mailto:rietveld_l@ill.fr> >
Subject: 答复: Le bail and rietveld method

 

Low temperature x-ray diffraction on Powdered single crystals was taken from 5 
to 80 degree with step size 0.02. The intensity of strongest peak is around 
1. Space group is Bb21m. 

 

The zero shift is quite large for both methods refinements. In GSAS, it is 
around -30.

 

发件人: rietveld_l-requ...@ill.fr <mailto:rietveld_l-requ...@ill.fr>  
[mailto:rietveld_l-requ...@ill.fr] 代表 Lucas Bonan Gomes
发送时间: 2016年6月15日 0:47
收件人: rietveld_l@ill.fr <mailto:rietveld_l@ill.fr> 
主题: Re: Le bail and rietveld method

 

Dear Jin,

Tell us about the parameters used in the analysis, such as step size.

Lucas Bonan Gomes.

Em 14/06/2016 13:32, Peng, Jin escreveu:

Dear Collegues: 

 

I am recently working on the structure refinement of some inorganic single 
crystals. I got the structure parameters from two ways: 

1.   Single crystal x-ray refinement;

2.   Low temperature x-ray diffraction on Powdered single crystals.  

I refined the powder x-ray diffraction pattern with both rietveld method and Le 
bail method. However, the Le bail refinement result is consistent with single 
crystal x-ray while the rietveld show divergence. Both a, b, c are remarkably 
high than other two method. For example, c is 19.573 for single crystal xrd and 
19.576 for le bail method. While for rietveld, it is 19.62.  

 

The powder x-ray pattern are taken from cuprate sample holder. I noticed that 
its peak position is around 0.15 degree lower (2theta) than the spectrum taken 
at glass sample holder. 

 

Jin





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Re: 答复: Le bail and rietveld method

2016-06-14 Thread Payzant, E. Andrew 
Probably the sample height has shifted due to thermal contraction. Not likely a 
zero shift.

Andrew



From: Peng, Jin 
Date: June 14, 2016 at 7:55:29 PM EDT
To: rietveld_l@ill.fr 
Subject: 答复: Le bail and rietveld method

Low temperature x-ray diffraction on Powdered single crystals was taken from 5 
to 80 degree with step size 0.02. The intensity of strongest peak is around 
1. Space group is Bb21m.

The zero shift is quite large for both methods refinements. In GSAS, it is 
around -30.

?件人: rietveld_l-requ...@ill.fr [mailto:rietveld_l-requ...@ill.fr] 代表 Lucas 
Bonan Gomes
?送??: 2016年6月15日 0:47
收件人: rietveld_l@ill.fr
主?: Re: Le bail and rietveld method


Dear Jin,

Tell us about the parameters used in the analysis, such as step size.

Lucas Bonan Gomes.
Em 14/06/2016 13:32, Peng, Jin escreveu:
Dear Collegues:

I am recently working on the structure refinement of some inorganic single 
crystals. I got the structure parameters from two ways:

1.   Single crystal x-ray refinement;

2.   Low temperature x-ray diffraction on Powdered single crystals.
I refined the powder x-ray diffraction pattern with both rietveld method and Le 
bail method. However, the Le bail refinement result is consistent with single 
crystal x-ray while the rietveld show divergence. Both a, b, c are remarkably 
high than other two method. For example, c is 19.573 for single crystal xrd and 
19.576 for le bail method. While for rietveld, it is 19.62.

The powder x-ray pattern are taken from cuprate sample holder. I noticed that 
its peak position is around 0.15 degree lower (2theta) than the spectrum taken 
at glass sample holder.

Jin




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答复: Le bail and rietveld method

2016-06-14 Thread Peng, Jin 
Low temperature x-ray diffraction on Powdered single crystals was taken from 5 
to 80 degree with step size 0.02. The intensity of strongest peak is around 
1. Space group is Bb21m.

The zero shift is quite large for both methods refinements. In GSAS, it is 
around -30.

发件人: rietveld_l-requ...@ill.fr [mailto:rietveld_l-requ...@ill.fr] 代表 Lucas 
Bonan Gomes
发送时间: 2016年6月15日 0:47
收件人: rietveld_l@ill.fr
主题: Re: Le bail and rietveld method


Dear Jin,

Tell us about the parameters used in the analysis, such as step size.

Lucas Bonan Gomes.
Em 14/06/2016 13:32, Peng, Jin escreveu:
Dear Collegues:

I am recently working on the structure refinement of some inorganic single 
crystals. I got the structure parameters from two ways:

1.   Single crystal x-ray refinement;

2.   Low temperature x-ray diffraction on Powdered single crystals.
I refined the powder x-ray diffraction pattern with both rietveld method and Le 
bail method. However, the Le bail refinement result is consistent with single 
crystal x-ray while the rietveld show divergence. Both a, b, c are remarkably 
high than other two method. For example, c is 19.573 for single crystal xrd and 
19.576 for le bail method. While for rietveld, it is 19.62.

The powder x-ray pattern are taken from cuprate sample holder. I noticed that 
its peak position is around 0.15 degree lower (2theta) than the spectrum taken 
at glass sample holder.

Jin




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