Least squares refinement from neutron polarimetry data
Description:
-
Main program for least squares refinement, of polarisation analysis data
from (possibly) mixed nuclear and magnetic structure factors
the magnetic symmetry is allowed to be less than the nuclear symmetry.
Input:
-
The crystal data file must contain all cards needed for magnetic
and nuclear structure factor calculations vis:
-
S cards
giving the symmetry.
A
C card
with the cell dimensions.
A cards
defining the atoms, their positions and isotropic.
temperature factors.
F cards
giving the magnetic and non-magnetic scattering
factors
Q cards
defining the magnetic structure
optionally:
-
T cards
giving anisotropic temperature factors
Additionally:
-
L cards
indicating which parameters should be refined
(see the CCSL users' manual)
I cards
which may have the words words NCYC, CYCL1, PRIN, MCOR CONV
and AXES
NCYC the number of least squares cycles (default 3)
CYC1 the number to be assigned to the first cycle (default 1)
- PRIN frequency at which output lists are printed
- PRIN = 0 no printing
PRIN = 1 first cycle
PRIN = 2 last cycle
PRIN = 3 first and last cycles
PRIN = 4 every cycle
MCOR controls the correlations printed at tyhe end of the job
- (default +70)
MCOR = 0 whole correlation matrix printed
MCOR = -ve no printing
MCOR = +ve correlations above MCOR printed
CONV convergence criterion; LSQ cycling is terminated if the
- maximum shift/esd < CONV (default 0.01)
AXES = 0 polarisations are given on crytallographic axes
AXES = 1 polarisations are given on "polarisation" axes (default)
A
P card
giving the incident polarisation
D cards
giving the crystal orientation
The data file which should be a list of the components of the incident
and scattered polarisation with repect to the axes implied by AXES as
written by CRYPAD (default extension .pol).
Output:
-
The usual listing file reporting the data which have been read. This file
also contains the output listings requested by the
I PRIN card
as well as
the R-factors and chisqrd at the end of each least squares cycle.
A new crystal data file corresponding to the structure at the end of the
least squares refinement.
Running the program:
-
On running the program the user is asked for the name of the crystal data
file and the name of the file containing the polarisation data.
The value of \$\chi^2\$ at the end of each cycle is reported on the
terminal.
After the last cycle user is asked for a name for the new crystal data file.
Calls:
- APSHSF
CALPOL
DFLTMG
ERRMES
GMEQ
GMPRD
GMSCA
GMUNI
INDFIX
LFCALC
LMCALC
LOGMAG
LSETUP
MAGCNL
MATCHF
MATCOR
MATINV
MATSET
MATSHF
MATTOT
MESS
NOPFIL
NWINSF
ONCARD
ORTHO
PARRUN
PARSSF
PREFIN
PRNCYC
REAPOL
RELATE
RFACS
SETFCM
SETPOL
STLSSF
UNIVEC
VARMAK
VARSMG
VECPRD
WGHTSF
Common blocks used:
-
- /DEPMAT/ to use all members
- /DGEOM/ to use UM
- /IOUNIT/ to use LPT ITO LUNI
- /NEWOLD/ to use AMAXSH
- /NSYM/ to use CENTRC
- /OBSCAL/ to use OBS GCALC DIFF NOBS
- /POLDA/ to use POLUP
- /POLDAT/ to use NDOMN ND180 POLIT POLM
- /POSNS/ to use NATOM
- /PRBLEM/ to use NFAM LF1SP
- /REFINE/ to use NCYC NCYC1 LASTCY ICYC IPRNT MAG CONV
- /SATELL/ to use IPROP
- /SCRACH/ to use all members
- /SYMMAG/ to use NMSYM MTYP NDOM HELI
*** PALSQ updated by PJB C105 April 2001 ***
Classification:
General Least Squares Refinement . . . . . . . Main Program
P. Jane Brown
e-mail: brown@ill.fr
Institut Laue Langevin,
Grenoble, FRANCE