Hi All,
I'm trying to fit an experimental Si pattern to refine the zero
offset for out instrument. The
calculated spectrum has 2 extra lines, and three missing lines.
I've hand calculated the
expected location of lines in the experimental spectrum and account
for all of the lines,
so I know I don't have the wrong spectrum or contaminated Si.
Here is the output of the reflist program. The last column has my
comments on the
calculated vs Si spectra.
H K L M sth/lam TTH FWHM FoSq
sig Fobs obs phase
1 1 1 8 0.1601852 28.5683 0.1502 4.288E+04 1.073E
+03 207.081 0 180.000
2 2 0 12 0.2615814 47.5278 0.1502 3.580E+04
896. 189.198 0 0.000 not in calculated pattern
3 1 1 24 0.3067313 56.3978 0.1502 8.852E+03
222. 94.086 0 0.000
2 2 2 8 0.3203704 59.1481 0.1502 262.
7.55 16.189 0 0.000 NOT ALLOWED, but calculated
4 0 0 6 0.3699320 69.4877 0.1502 1.109E+04
278. 105.328 0 0.000
3 3 1 24 0.4031239 76.7853 0.1502 5.422E+03
137. 73.632 0 0.000
4 2 2 24 0.4530722 88.5339 0.1502 5.947E+03
150. 77.114 0 0.000 not in calculated pattern
3 3 3 8 0.4805556 95.5218 0.1502 1.914E+03
48.8 43.744 0 180.000
5 1 1 24 0.4805557 95.5218 0.1502 1.913E+03
48.8 43.736 0 180.000
4 4 0 12 0.5231627 107.4119 0.1502 1.693E+03
43.3 41.142 0 0.000
5 3 1 48 0.5471367 114.9008 0.1502 503.
13.6 22.427 0 0.000
4 4 2 24 0.5548979 117.4937 0.1502 226.
6.64 15.019 0 0.000
6 2 0 24 0.5849137 128.6134 0.1502 522.
14.1 22.849 0 180.000 not in calculated pattern
5 3 3 24 0.6064515 138.2340 0.1502 265.
7.63 16.288 0 0.000
6 2 2 24 0.6134627 141.8573 0.1502 166.
5.15 12.887 0 0.000 NOT ALLOWED, but calculated
0 0
0
-100.0000 1
Where I say "not in calculated pattern", I mean that I don't see any
indication of a line at that 2theta in the LivePlot spectrum.
By "NOT ALLOWED, but calculated", I mean that the reflection is
extinguished by destructive interference, but that the
program has place a line at that location.
I also looked at the data in what I think is the reflection file
from PowPref: expfilename.R01. That file has the same information
given by reflist. The GSAS manual says that the name should
be expfilename.Pnn, but the file by that name doesn't at all match
the file format given in the manual.
I would appreciate any suggestions on where I'm going wrong.
Thanks,
David Lee, Ph.D.
SMRL, The Ohio State University
Dept. of Materials Science and Engineering
2041 College Rd
Columbus, OH 43210
(614)-688-3182
