Brian H. Toby wrote:
I am trying to convert a GSAS ESD file to a GSAS STD file
BTW, I would be surprised if FullProf does not have a way to input
intensities with uncertainties rather than assuming intensities are
counts.
Indeed it does! INSTRM=10 is x, y, sigma format for fullprof where it
takes the first 6 lines as comments and computes sqrt(I) only if you
don't supply the sigma.
Some years ago I did see the reverse process of an x, y, esd file being
mangled by some conversion program on the way to becoming GSAS format,
but I forget the culprit. Quite surprisingly I see GSAS2CIF also
truncates, but at least only corrupts the data by a fraction of an esd. eg:
BANK 1 9019 1804 CONST 0.200 0.200 0.0 0.0 ESD
26.5 5.7 18.9 4.4 24.4 5.1 17.2 4.4
17.4 4.4
becomes:
loop_
_pd_meas_intensity_total
_pd_proc_ls_weight
_pd_proc_intensity_bkg_calc
_pd_calc_intensity_total
27(6) 0.0 -309450.1 .
19(4) 0.0 -299678.4 .
24(5) 0.0 -290192.4 .
17(4) 0.0 -280984.3 .
Is there any chance of seeing
_pd_meas_angle_2theta
<http://www.iucr.org/iucr-top/cif/cifdic_html/1/cif_pd.dic/Ipd_meas_angle_.html>
(or ToF, Energy) etc being added as a column and the sigma being in a
separate column instead of in brackets? I didn't see a cif label for
this column but the bracket notation is annoying to either parse or
output (the mmcif people seem to be allowed to use *_esd). It seems that
one could even give the "right thing" to copy+paste to an x,y,esd file,
if the spare columns are at the end.
Seems that most conversion programs will screw up if they are doing
something they weren't supposed to do. Wherever possible try to go back
to the "raw" data file from the instrument and process it directly into
the format you want.
Jon
