Contents Prev Manual

PROGRAM ABSMSF

To read ARRNGE files, apply absorption corrections and calculate
mean structure factors

Description:

The program reads a file written by an "arrnge" type program.
Then, if G cards are present, it calculates and applies absorption corrections to the measured intensities. The program then calculates the weighted mean of all measurements of reflections which should be equivalent and deduces the mean structure factor.
A statistical analysis is made of the degree of reproducibility of multiple measurements of the same reflection and on the degree of equivalence of symmetrically equivalent reflections. The mean overall reflection intensity is calculated in order to facilitate the estimation of a scale factor.

Input:

The crystal data file must contain:
S cards giving the symmetry.
A C card with the cell dimensions.
I cards (the same as were used with ARRNGE). These define the type of data, how many additional parameters such as angles were stored by ARRNGE, etc.

The following are optional
D cards describing the diffraction geometry.
G cards describing the crystal shape.

If either is absent no absorption corrections will be made.
The data file is that written by ARRNGE. Default extension ".arr"

Output:

The usual listing file reporting data read from the CDF. It also reports the results of the statistical analysis.
An optional second listing file giving the absorption corrections. It is called ABSCOR.LIS and will only be produced if there is an OUTP 100 entry on an I card .
The output file, which will have default extension ".sf", contains a list of hkl, Fobs, esd(Fobs) in a format suitable for input to least squares programs: MODE 3 for integer indices and MODE 6 for floating indices.

Notes:

If extinction corrections which are not path sensitive are to be made the extinction coefficients required by least squares programs can be obtained by running EXTCAL on the files written by ABSMSF.
Note however that if the paths for different reflections differ significantly then equivalent reflections should be treated independently and AVEXAR rather than ABSMSF should be used to process the ARRNGE output files.

Running the program:

On running the program the user is asked for the name of the crystal data file, the reflection data file (.arr) and is then asked to choose the name for the output file (.sf).
The results of the statistical analysis are reported on the terminal.

Calls:

ABSCOR ERRMES ICDFMT INPUAR INPUTI NEWPAG NOPFIL PREFIN RECIP SETABS STATIS SYMOP TESTP

Common blocks used:

/ABSDAT/ to use MODEA
/IOUNIT/ to use LPT ITO
/REFS/ to use SCALE INC II ITEMS
/SCRACH/ to use NAMFIL
/STATS/ to use AMEAN DEV SUMS

*** ABSMSF updated by PJB 7-July-1995 ***

Classification:

Data Collection and Reduction . . . . . . . Main Program


Contents Manual

P. Jane Brown e-mail: brown@ill.fr
Institut Laue Langevin,
Grenoble, FRANCE