[RMCProfile-users] .inst file by GSAS2

Von Dreele, Robert B. vondreele at anl.gov
Thu Jul 7 14:16:30 BST 2022

Dear Reona,
The nice thing about GSAS-II is that you can look at the code. In GSASIIpwd.py are the setup utilities for RMCProfile. Lines 2675-2686 are what made the contents of the .inst file. You have mostly correctly identified the items; they are:
3 blank lines

The ‘1’, ‘0’ & ‘0.0’ entries are unused placeholders; GSAS-II ‘Z’ is not used in RMCProfile. Your ‘Y’ value is quite large; there must be a lot of “mustrain” broadening in your sample. Perhaps that is part of the reason for doing RMCProfile & moving atoms will sort it out. I can’t see your attachments (I get warnings about it being “unsafe”) so I can’t comment.

Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows

From: Reona Miyazaki via rmcprofile-users<mailto:rmcprofile-users at shadow.nd.rl.ac.uk>
Sent: Thursday, July 7, 2022 6:01 AM
To: rmcprofile-users at rmcprofile.org<mailto:rmcprofile-users at rmcprofile.org>
Cc: miyazaki.reona at nitech.ac.jp<mailto:miyazaki.reona at nitech.ac.jp>
Subject: [RMCProfile-users] .inst file by GSAS2

Dear all

I am a beginner of RMCProfile 6.7.9 user and now performing RMC simulation
using Xray F(Q) data.

My question is about .inst file.

Several parameters are found in .inst file, but I cannot clearly understand
which parameters indicate U, V, W, X, Y, Z etc..

At first, I have performed Rietveld analysis by GSAS II for making the
initial structure for RMC.

After that, the initial configuration file (.rmc6f) and 5 sets of files
(.bragg, .dat, .back, .xray and .inst) required for RMC were created by GSAS

Using these dataset, I have started RMC.

But, even for the initial Bragg data(without any movement of atoms), the
large difference was observed between the experimental and calculated data.

The results were attached. The two legends (Calculated and Experiment) are
opposite, though I don't know the reason...

The calculated data does not reproduce the experimental data(left), although
the Rietveld results (right) seem to be reasonable.

I have checked .inst file(below).



   0.20240(wave length)   0.07129(scale?)    0.9590(Polariz.)         0(?)

   20.000(U)   -12.000(V)     4.172(W)

   1.518(X??)   103.298(Y??)     0.000(Z??)

   0.000(??)     0.000(??)     0.000(??)


It seems UVW values are the same with those derived by Rietveld analysis.

But X and Y are slightly changed and I cannot find Z and SH/L values
anywhere in .inst file.

The profile parameters have been changed during the creation of .inst file

I consider this is one of the origins that Bragg data cannot be reproduced
by RMCProfile.

In addition, the last triplet "0.000" values are completely unclear.

It seems "1.0" should be added at the end of line of .inst file.

Please tell me the meanings of the parameters in .inst file and the proper
way to reproduce the Bragg peaks in RMCProfile.

Best regards

Reona Miyazaki

Physical Science and Engineering,

Graduate School of Engineering,

Nagoya Institute of Technology

Gokiso-cho, Showa-ward, Nagoya city, Aichi 466-8555, Japan


mail:miyazaki.reona at nitech.ac.jp <mailto:miyazaki.reona at nitech.ac.jp>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.rmcprofile.org/pipermail/rmcprofile-users/attachments/20220707/852eaf1d/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: results.png
Type: image/png
Size: 217820 bytes
Desc: not available
URL: <https://lists.rmcprofile.org/pipermail/rmcprofile-users/attachments/20220707/852eaf1d/attachment.png>
rmcprofile-users mailing list
rmcprofile-users at rmcprofile.org

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.rmcprofile.org/pipermail/rmcprofile-users/attachments/20220707/fdc93de9/attachment.htm>

More information about the rmcprofile-users mailing list