The XND program for crystal structure refinement of powder data was writen 
in order to take into account the correlations between data obtained in 
real-time experiments for which the statistical quality of each diagram 
is very low.
Line profiles are represented by Voigt functions, new terms have been 
added to describe the evolution of line width and asymmetry.


Following files are copied on the floppy:

 xnd.exe        PC program

 xnd_sym.d
 xnd_dif.d      symetry and diffusion files, to be located in the same
                directory than xnd.exe

 xnd_doc.d      user doc, in french , it needs many improvments
 xnd_ins.d      technical doc, in french, needed to compile sources

 xnd_tim.v      typical run time for various computer
 xnd_ver.v      history of modification

 xnd_1.k        a short example use to generate articial data
 xnd_2.k
 xnd_2.dat      a neutron example
 xnd_4.k        the input file for neutron data at various temperature
 xnd_6.k        a x-ray example.

 xnd_bat.bat    a bat file to restart refinement on PC

 vis-diag.exe   a simplified program which allow to see the various plot
                generated by xnd on a PC. The program searchs for the
                Borland Graphic Driver in /dos/tc or in the current
                directory. It uses the string ".plg" to recognise the
		xnd graphic file. It can produce a HPGL print.
		You can either it by "vis-diag name.plg" or "vis-diag"
		and use the L (lecture) command to read files.
		Other internal commands are Q (quit), C (curve) to
		change curves attributes (symbol, color, line) and X or
		Y to change the view giving xmin and xmax.

 
 I hope the examples will help you.

 A new definition of the asymmetry is now used in xnd, description
 is given in "Modeling of line-shape asymmetry in powder diffraction"
 to appear in JAC 1993.

 Let me know your questions and if you use it. You can E-mail to
 berar@cps.ecp.fr  (or berar@lure.lure.ups.circe.fr)