STOE IPDS: Software Features

Version 2.86 11/1997

Examination of Twinned or Grown-together Crystals

STOE provides a complete package for measuring and evaluating intensities of twinned or grown-together crystals on the IPDS:

Frames		Collecting images is as easy as for single crystals
Peak search		Automated multi-frame search; unlimited number of peaks
Indexing		Graphics-supported analysis to separate and index peaks
Intensities		Simultaneous integration of reflections from up to three (!) domains
HKL files		Output of standard reflection files (SHELX-formatted)
Graphics		Visualization of cells in a reciprocal space coordinate system
Cell		Post-refinement of cell, possible for all orientation matrices.

Convenient Diffractometer Control

Complete, safe and easy control of the instrument
Automatic data collection or individual exposures
Control of the new Dual-Mode Goniometer Head provided
Graphical program surface with representation of currently recorded image
Survey of image statistics, measurement time and hard disk space

Sophisticated Visualization of Images

Intensities on linear or quasi-logarithmic scales
Automatic or manual intensity scaling
Magnifications of image sections in eight steps with memory function
2q, d_hkland h k l from mouse-determined positions
Superposition of simulated patterns onto frames

Automated Peak Search

Unlimited number of peaks; quality of results defined by significance test
Superposition of observed peaks onto image for control purposes
Automated peak search from subsequent images provided (multi-frame search)

Powerful Indexing of Reflections

Indexing of up to 2000 reflections from any crystal orientation
STOE method is as well useful for crystals with very large (longest axis > 250 Å) as for extremly small (shortest axis < 4 Å) lattice parameters
Easy and definite recognition and indexing of superstructure reflections
RECIPE: Novel tool for the indexing of peaks from obstinate crystals (twins, ...)
Automatic (and manual) cell reductions and cell transformations provided
Precaution for right-handed systems and for rhombohedric unit cells
Automated recognition of centred unit cells

Fast Integration of Reflections

Profiles Automated integration profiles, visible during the integration
Diagrams Graphical and numeric control for highest possible quality of intensities
Matrix Refinement of orientation matrix after each processed frame
Overlap Automated recognition of overlapping or overloaded regions
Output Included data reduction and output of SHELX reflection file
Cell Output of reflection positions for post-refinement of cell parameters
Time Fast routines; parallel processing during data collection possible

Sections of reciprocal space

A powerful tool called SPACE provides representations of undistorted layers of the reciprocal space (similar to Buerger exposures), using pixel data from all available frames.

Easy definition of desired layer
Layer pictures are composed of pixels from all available frames
Sophisticated macro handler for calculating several layers in one run
Batch mode for processing a macro (e.g. overnight)
Grafic representation of layer pictures on the screen (including zoom, ...)

Complete Data Reduction

Correction of Lorentz polarization + air absorption
Combination of partially recorded reflections
- Default: Standard SHELX reflection file (h, k, l F_o², s(F_o²), direction cosines)
- Incommensurate crystals: Extended SHELX format (containing six indices)
- Output of a communication file for X-STEP
- Interface for CRYSTALS provided
- Conversion to CCP4 format possible

Crystal Decomposition

Representation of crystal decay by a diagram
Correction function for crystal decomposition with variable smooth factor
Graphical control of correction function

Corrections for Crystal Absorption

FACEIT:
Easy determination of crystal shape;
numerical absorption correction
X-SHAPE^*:
Automatic refinement of crystal shape including graphics
ABSCOR:
Empirical absorption correction including
F_o²/F_c² comparison
X-RED:
Spherical absorption correction, numerical absorption correction

Additional devices (e.g. optical goniometer) are no longer needed.
All correction methods are based on F_o².

^*X-SHAPE is a STOE version of HABITUS (Author: Dr. W. Herrendorf) running under Windows95?.

Scaling and Merging of Two Data Sets

Unlimited number of reflections from two data sets for the merging
The data sets may come from completely different measurements
(with different collimators, generator powers, irradiation times or crystals)

Prediction of Reflection Positions

Input of indices of the desired reflection, output of all possible j/X/Y coordinates
Automated loading of a corresponding image; and the reflection is highlighted
Non-integer indices, important for verification of superstructure reflections

Determination of the Laue Group

Graphical representation of measured reflections within reciprocal space to determine the correct Laue group, especially with strongly absorbing crystals

Automated Space Group Determination

Easy-to-use, runs on a PC under Windows?
Automated analysis of systematically absent reflections (manual interaction possible)
E-statistics including graphics for the distinction between centrosymmetric and non-centrosymmetric space groups
Automatic transformation to standard setting if necessary
Merging of symmetry-equivalent reflections for a given space group

Examination of Incommensurate Crystals

Comprehensive package for handling data from incommensurate modulated crystals, including:

Collecting images
Indexing the main lattice
Determination of q vectors
Extracting intensities from images

Connection between IPDS and 4-Circle Diffractometer

Easy mechanical matching of the crystal position on the j-axis of the IPDS to the crystal position on the j-axis of the STADI4
Automated transformation of an IPDS orientation matrix into a STADI4 matrix, enables fast and convenient transfer of a crystal from the IPDS onto a STADI4 for further data collection

Creation of 'Powder Diagrams'

Every image may be transformed into a 'powder diagram'
Linear and circular cuts through images provided, which leads to:
- Intensity as a function of 2q (linear cut)
- Intensity as a function of c (circular cut)
Any section of an image can be transformed
A list of d values can be superimposed on an image (indexing and identification tool)
The d list may be taken from Visual X^POW, the STOE software package for powder diffractometry.

Created: 09.05.1996 - Updated: 10.07.98