Least squares refinement from magnetic structure factor data
Description:
-
Main program for least squares refinement, of magnetic structure factor data
from (possibly) mixed nuclear and magnetic reflections
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 and CONV
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 the 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)
One or more data files which should be lists of hkl and observations of the
type and in the format indicated by the values of REFI and MODE. For
single data sets MODE and REFI may be given on an
L card
, but with multiple
data sets they must be given interactively along with the file name. The
relative wieghts to be given to different data sets is also given there.
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 structure factor data.
The value of \$\chi^2\$ at the end of each cycle is reported on the
terminal.
Just before the last cycle user is asked for a name for the new crystal
data file.
Calls:
- APSHSF
CALCFR
CALCGM
CALCMG
CENTRE
DFLTMG
ERRMES
GMEQ
INDFIX
LFCALC
LMCALC
LOGMAG
LSETSF
MATCOR
MATINV
MATSET
MATSHF
MATTOT
NWINSF
PARRUN
PARSSF
PREFIN
PRNCYC
RELATE
RFACS
SETABS
SETFCM
STLSSF
VARMAK
VARSSF
WGHTSF
Common blocks used:
-
- /DERBAS/ to use LVARB
- /DSOURC/ to use NUMSRC JSRC MSRC NOBSRC SRCPAR
- /EXTN/ to use IEXTYP CEXT PATHS
- /FCAL/ to use FCMOD
- /IOUNIT/ to use LPT ITO
- /MCAL/ to use FMCMOD
- /NEWOLD/ to use AMAXSH
- /OBSCAL/ to use OBS GCALC YCALC DIFF SUMWD WT
- /POLDA/ to use POLUP POLDW POLND
- /POSNS/ to use NATOM
- /PRBLEM/ to use NFAM LF1SP
- /REFINE/ to use IREF NCYC NCYC1 LASTCY ICYC MAG CONV
- /SFDATA/ to use NDATA HS GOBS WGTS JSCALE CPARS
- /SCLDAT/ to use ISCALE SCALE
- /SYMMAG/ to use MTYP FERA HELI
*** MAGLSQ updated by PJB C4.1 multiple data sources December 2006 ***
Classification:
General Least Squares Refinement . . . . . . . Main Program
P. Jane Brown
Institut Laue Langevin,
Grenoble, FRANCE