1.3.5.5 – ABSX – Crystal Dimension Optimization
Crystal description optimization on the basis of psi-scan data. Numerically corrected psi-
scan data are displayed in comparison with the experimental curves. The geometry of the
crystal can be changed manually in order to investigated its impact on the fit of both curves.
Sub-Menu #0 – (
Section 1.4.16) – Options
1.3.5.6 - ABSS - Spherical Absorption Correction
Correction for absorption of a spherically shaped crystal. The correction is based on
'Dwiggens (1975)'
Sub-Menu #0 – (
Section 1.4.16) – Options
Two data input files are required:
1.
name.ins : instruction file:
2.
name.hkl : reflection file: (hkl F^2 sig(F^2) + direction cosines) with SHELXL
HKLF 4 format (3I4, 2F8.2,I4,6F8.5).
Input data on
name.ins
TITL titl
CELL lambda a b c alpha beta gamma
ABSS mu radius
Notes:
- mu and
r should have the same (reciprocal) dimension.
- r is radius, not diameter !
Calculations are invoked with:
platon name.ins
The corrected data are on:
name.hkp
1.3.5.7 - SHXABS - Empirical Absorption Correction
Empirical correction for absorption based on the modeling of the absorption surface with
spherical harmonics using the difference between I(obs) and I(calc). This implementation is
similar but not identical to SHELXA. I(obs) is calculated from the model present in the '.res'
file. This file may contain a HKLF line carrying a transformation matrix.
The correction is attempted, based on a
.res and
.hkl file. Structure factors are calculated
based on the data in the '.res' file.
The 'corrected' data are written to a
.hkp file.
Note: the usual warnings for the application of empirical correction techniques apply.
1.3.5.14 - XtlPlanAng – Crystal Plane Angle Calculation
This option allows for the calculation of the angle between two crystal faces. The angle
request can be entered as the keyboard instruction:
ANGLE h1 k1 l1 h2 k2 l2 where h1 k1
l1 and h2 k2 l2 are the respective sets of plane indices. The input to the program should at
least contain the cell dimensions (e.g. a
.res or a
.cif).
1.3.5.15 - XTAL HABIT – Display of a Face Indexed Crystal
A drawing of a crystal is generated based on a supplied face-indexed description.
Sub-Menu #0 – (
Section 1.4.16) – Options
Example file
xtal.ins:
TITL XTAL
CELL 3.1304 3.1349 16.9117 90 90 90
FACE 1 0 8 .0434
FACE -1 0 8 .0434
FACE 1 0 -8 .0434
FACE -1 0 -8 .0434
FACE 0 1 8 .0651
FACE 0 -1 8 .0651
FACE 0 1 -8 .0651
FACE 0 -1 -8 .0651
FACE 0 0 1 .0325
FACE 0 0 -1 .0325
Invoking PLATON with
platon xtal.ins followed by either clicking on the
XTAL HABIT
menu-item or by typing
XTAL will bring up a drawing of the crystal and the ABSCOR-
MENU. The crystal drawing can be stepwise rotated by clicking on the RotX, RotY and
RotZ buttons. Faces may be added, changed or deleted (Either by clicking on the Menu-
items FaceAdd & FaceDelete or from the Keyboard)). E.g. adding an additional (1 0 0)
plane is accomplished with the keyboard instruction
FACE 1 0 0 0.06 and the deletion of
the (0 0 1) face with
DELF 0 0 1 . The current number of faces, edges and vertices is
displayed on the drawing. The crystal is checked for finiteness using Eulers rule that:
Number of Planes + number of Vertices = number of Edges + 2. If not, the message Crystal
not Finite is issued.
END or
EXIT will terminate the session.
1.3.6.1 - Validation – Validation Tests on CIF(+FCF) & CCDC-CIF-data
This Tool performs a CIF validation and, when supplied, also an FCF Validation. See
Chapter 8 for
more details. The CIF file can be a multi-entry file. The data names for
corresponding entries in the two files should be identical. The result is displayed with copies
on files extensions
.chk and
.ckf. The alternative terminal window command for this
analysis is:
platon -U name.cif. Documentation of the validation report can be found in
http://www.cryst.chem.uu.nl/spek/platon/CIF-VALIDATION.pdf
and
http://www.cryst.chem.uu.nl/spek/platon/FCF-VALIDATION.pdf.
1.3.6.2 – ASYM-VIEW – Inspect the Data in Diffraction Sphere Sections
This PLATON tool may be used to get an overview over a data set in reciprocal space as a
function of resolution, data quality, completeness and missing data. A
.res or
.cif parameter