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Examples files.
Examples files.
Contents
Very short example without data creating a simulated pattern. It is
a short way to verify if xnd runs and finds its default files.
This a input file to be used the the data file xnd_2.dat
.
a neutron data file example with its data file
5400 points, 39 variables (28 parametres), 4 cycles max
Rwp=0.0897 Rp=0.0681 S : 5580 GoF 1.02
The current xnd_2.k file can use the new file structure, however the
old example file renamed "xnd_2_1.k" should give the same result.
xnd_3.k + xnd_3.dat
a x-ray (generator) data file example with its data file
Rwp=0.1454 Rp=0.1133 S : 15888.63 / 1.81
This file is still an old style input file but the new file will
be written according to xnd_1.2 style.
xnd_4.k + xnd_4.dat
a neutron data file example for incomensurate phase
example of input file with temperature dependancies
xnd_6.k + xnd_6.dat
a x-ray data file example with phase profiles
xnd_7.k + xnd_7.dat
short file for single line fitting
short file generating lines on simulated pattern
short file simulating quasi crystal pattern
example of input file for a composite structure
Some applications need to known the absolute intensity received
by the sample. The following lines show how such a calculation can
be done using xnd scale factor. It uses the relation between
intensity and flux as described in a paper from Suorti
(Acta Cryst A41 (1985) p413), the definition of functions
in xnd. Note that the coefficient 180/Pi arises from
the fact that angles in data file are the degrees and therefore
the integrated intensities.
The relation between the flux No and the scale factor
Scale can be written as :
No = 32 Pi^2 Scale Mu Vc^2 / (180 Eff RSlit VDiv Re^2 Lamda^3)
with, using values from Al(OH)3, as example :
Symbol | Value | Comment
|
---|
Re | 2.82 E-15 m
|
---|
Vc | 425 E-30 m^3 | Cell volume
|
---|
Lambda | 1.54 E-10 m | Wavelength
|
---|
RSlit | 0.029 deg = 5 E-4 rad | Receiving slits (rad)
|
---|
VDiv | 2.3 deg = 4 E-2 rad | Vertical divergency (rad)
|
---|
Eff | 1 | Efficiency and air absorption
|
---|
Mu | (3x.43+48x11.5+27x48.6)/(3+48+27) x 2.4
|
---|
57 cm^-1 = 5.7 E3 m^-1 | Sample absorption
|
In this case we have No = 3.10 E12 Scale
JFB Feb 21th, 1997