To calculate the positions and intensities of the lines in a
powder diagram
Description:
-
POWDER reads a crystal data file and, using a wavelength given
interactively, calculates the angles 2\$\theta\$, at which reflections will
occur. For each reflection the square of the structure factor, the
multiplicity, the factor relating Fsq to intensity, and the intensity
of the corresponding powder line are tabulated.
Input:
-
The crystal data file must contain:
-
S card
(s) giving the space group symmetry (note that a
single card saying "S GRUP n" card should suffice n
is the space group number)
A
C card
with the cell dimensions
A cards
with the atomic positions
F cards
with the form factors or scattering lengths
Output:
-
A listing file: powder.lis which reports how the crystal data file
was interpreted and gives the results of the calculation. The results
columns are headed:
- h k l: for the reflection indices
2theta: for the scattering angle
Fsqrd: for the square of the structure factor
Mult: for the multiplicity of the powder line
Factor: gives the factor by which the intensity should be
- multiplied to get Fsqrd. (\$\sin\theta\sin2\theta/m\$)
Intensity: The expected intensity of the powder line
The format of the results file, if one is requested
is (3I5,F10.4,2f10.2) and contains hkl, 2\$\theta\$, Intensity, Factor,
for each reflection.
Running the program:
-
On running the program the user is asked for the name of the crystal data
data file, the wavelength, the maximum and optionally the
minimum 2\$\theta\$ for which results are required; also whether the
results should be written to a file, if so the name of the file is requested.
Calls:
- ASK
CENTRE
DEGREE
ERRMES
FCALC
GENMUL
INDFIX
JFIX
LATABS
MESS
NOPFIL
PREFIN
RADIAN
RDNUMS
SAYS
SETFC
SETGEN
SORTN
SYMUNI
TESTP
VCTMOD
Common blocks used:
-
- /BRAGG/ to use STHL
- /IOUNIT/ to use LPT ITO
- /SCRACH/ to use NAMFIL
*** POWDER by PJB Nov 1995 ***
Classification:
Data Collection and Reduction . . . . . . . Main Program
P. Jane Brown
e-mail: brown@ill.fr
Institut Laue Langevin,
Grenoble, FRANCE