Convert and more

Nita.Dragoe ( Nita.Dragoe@chimsol.u-psud.fr )
Sat, 10 Feb 1996 12:51:06 +0100 (MET)

Hi,

A new version of Convert is available at

ftp.minerals.csiro.au/pub/convert
A description follows at the end of this letter.

On the other hand, in the last period all the letters I had from
the rietveld user group were with UNSUBSCRIBE !!
I do not know why but I think that it cames from a sort of
inactivity. Not only for this reason I try to open a 'forum' of
discussion by asking something relative to the Rietveld method.

In the Rietveld method book (Ed. RA Young) someone (i guess is
Hill) wrote that the modulation (i reffer thereafter only to
the incommensurate one) could affect the position and the shape
of the diffraction profile. It is quite normally when the
diffraction take place on a d* that contain a modulation vector, but
not when the line is a main one and not a satellite (am I wrong?).
For instance, taking a platelet like monocrystal, whith the c axis
normal to the platelet. This crystal has the modulation vector
as 0.186b*+0.5c* (determined by precession and ED).
Making a diffractogram (we have now only 00L lines ) I found that
the 005 lines and the 006 lines give a different c-axis value. This
difference is about 0.15 angst. I checked the diffractometer (a
good Philips) I changed the optics etc.
I have done this also with a Siemens and no cure.
The questions:
-what is the origin of this difference ? (it may be a
banal one but I don't see)
-if it is the modulation (I guess) in what way?

Thank you very much

N Dragoe
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1996, February
The version Convert 2.0d uploaded at ftp.minerals.csiro.au
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There are for files:
convert.zip -the program itself
vbrun300.zip -a Windows DLL routine
cmdialog.zip -two DLLs
convert.txt -this file
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CONVERT 2.0d

This program can (sometimes..!) convert some ASCII data files. It was
intended to use in X-ray diffraction area (Rietveld analysis or so..)
for converting the data files. There are a lot of programs dealing
with data analysis, fitting profile, Rietveld analysis,... and almost
each program has a different way of reading data (many of them written
in Fortran and asking a "rigid" data file). Sometimes, a user work with
different programs and he needs to convert his data file into
various others (somebody told me :"Who hasn't a data converting program ?").
So, this program will try to convert such data files....

There are also few programs dealing with that too (I found that AFTER
I started to write this program....)

This program is free for noncommercial use.
Anyway I ask to send me a letter by e-mail or better by snail-mail
if you are using this program (I want to see if it's worth or not to
develop this software).

This program is written in Visual Basic 3.0 (you will need a vbrun300.dll,
cmdialog.vbx and comdlg.dll in the windows/system directory; sometimes there
are already there so don't waste your time to load them again).

It is the user's duty to choose the input format - and the output of course.

This program can convert with/without the header lines (I choose this way because
it may be useful to other users -dealing or not with X ray diffraction).

It reads :

-BIGDIFF data file and convert to fixed step data file
(the interpolation scheme is correct as long as the
difference between the 'real' 2theta and programed one is smaller than
the step...) (without header)

-DBWS for PC (with/without header)

-WPPF/Profit (with/without header)

-standard Ascii column format (x, y or y free format)

-Scintag (without header)

-Philips UDF (with/without header)

-XND

-GSAS (esd or std, with/without header)

-Xpas, Riet.

and possibly other (someone told me that the Siemens ascii file can be converted
deleting the definition lines as a DBWS file, try it.)

You could apply some factors to the data depending with x, y or esd ;
a factor depending with x could apply to y. Look in the help explanation
about that factor. Anyway it must written as:
a_factor*x^another_factor
and it is an ADD factor .
Don't write -x or something like that... Write -1x or -1*x.
(It seems to be rather difficult but I made a routine trying to
convert such an expression to a number...,I would change that sometime)

If it is needed you will be asked for starting two theta, step...and so on.

How many lines can you use ? As many as your computer can store ! It may
work slow because but that is...

Anyway , the author does not assume any responsability ....

For help or errors (I'm sure that there are few errors but I couldn't
find them...) or comments please feel free to contact me:

N. DRAGOE
University of Bucharest
Faculty of Chemistry
Blvd. CAROL I, #13, Bucharest
ROMANIA

dragoe@roimar.imar.ro
ndragoe@math.math.unibuc.ro

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