|
Purpose
Crystal structure solution from powder diffraction data by a combined global
optimization of the difference between calculated and measured diffraction
pattern and of the potential energy of the system ("Pareto optimization")
Functions
Structure Solution:
-
Structure solution from conventional X-ray laboratory diffractometer as well as
synchrotron, neutron or electron diffraction data. Input needed: cell
parameters, peak list (2 theta vs. intensity; no profile step-scan data;
imported from Philips, Bruker-AXS, Stoe) or |F(hkl)| list (e.g. imported from
SHELX-file), contents of the unit cell (composition or molecular structure plus
number of the formula units).
-
Wizard for the easy preparation of the structure solution process (settings for
pattern, composition, and potential parameters).
-
Viewing of the intermediate steps of the structure solution process: progress
(% finished), R-Value, list of correlated calculated and observed peaks,
structure picture, and diffraction diagram in user-defined arrangement
side-by-side.
-
Auto Build function to visualize the crystal structure of each intermediate
step, e.g. the unit cell, with or without bonds, with or without polyhedras,
molecules, etc.
-
Report View displaying the results of Pareto optimization as formatted text,
that can be copied to clipboard, saved, or printed.
-
Easy editing, calculation, and fitting of potential parameters (simple
repulsion, Lennard-Jones).
-
"Hofmann" potential, enabling much easier solution of crystal structures
of rigid molecules (D.W.M. Hofmann, L.N. Kuleshova, Crystallography Reports 50
(2), 372-374 (2005)). The potential is even capable of predicting the crystal
structures of rigid molecules without using any powder diffraction data: D.W.M.
Hofmann, J. Apostolakis, "Crystal structure prediction by data mining", J. Mol.
Struc. (Theochem) 647, 17-39 (2003). The new potential does not contain any
parameters which have to be adjusted by the user, so that its usage is
extremely simple.
-
Symmetry Finder with automatic or interactive transformation to higher space
group.
-
"Structure Solution" by either energy minimization or diffraction data alone is
possible.
-
Support for molecular as well as for atomic crystal structures.
-
Manual selection of rotatable bonds within the molecule(s) for variation during
structure solution calculation.
-
Import of 3-dimensional molecular strures from various file formats including
Diamond (*.dsf), Cambridge CSD-FDAT (*.dat, *.fdat, *.csd), MDL Molfile/SDFile
(e.g. from ACD ChemSketch) (*.mol, *.mdl, *.sd), Cerius2 CSSR (*.cssr, *.dat),
Sybyl MOL/MOL2 (*.mol, *.mol2) and CIF (*.cif) files.
-
Molecules can also be sketched and transformed into 3d using ACD ChemSketch
Freeware which can be installed from the Endeavour 1.1 CD-ROM.
Structure Visualization:
-
Manual input or change of structural parameters and bibliographic data.
-
Imports structure data from crystal structure databases (Inorganic Crystal
Structure Database, Cambridge Structural Database, Protein Data Bank), from
Pauling File (Inorganic Material Database), from Crystallographic Information
File (CIF), from SHELX format, as well as from several molecular structure
formats.
-
Creating contents of unit cell, super-cell, or any arbitrary range of the
crystal lattice.
-
Discussion of connectivity assisted by histograms showing the distribution of
distances between selected atom types, together with automatic calculation of
distance ranges.
-
Completion of coordination spheres around selected atoms.
-
Generation of molecules or completion of molecular fragments that have been
clipped at the cell edges (packing diagrams).
-
Ball-and-stick, wire, and space filling model. Central or parallel projection,
depth cueing, stereo display.
-
Photo-realistic rendered models with user-defined light source and material
properties (OpenGL).
-
Rotating, shifting, and zooming: mouse-controlled, step-by-step by keyboard, or
numerically. Views along specified axes or towards hkl-planes.
-
Coordination polyhedra around selected atoms or manually constructed, with
hatched, opaque, or transparent faces.
-
Display of thermal ellipsoids to visualize anisotropic displacement parameters.
-
Labelling of atoms and bonds. Variation of colors, styles and radii of atoms
and bonds, either by type or individually assigned.
General:
-
32 Bit MS Windows 95/98/ME/NT/2000/XP application with Multiple Document
Interface (MDI), context-sensitive menus, and toolbars. Allows "simultaneous"
handling of multiple structures.
-
User-defined arrangement of structure picture and diffraction diagram as well
as several textual data side-by-side.
-
Multiple-step Undo and Redo function.
-
Calculation or interactive measuring of distances, angles, and torsion angles,
including standard uncertainties.
-
Export to crystal and molecular structure formats, peak and |F(hkl)| formats,
Windows metafile, several bitmap formats, as well as to Virtual Reality
Modelling Language (VRML).
-
Online update (automatic or manual).
System requirements
-
Personal computer with MS Windows® 95/98/ME or MS Windows NT® 4.0/2000/XP
-
Processor: Pentium II ® or higher
-
32 MByte RAM
-
Minimum graphics resolution of 800x600 / 16-Bit (1024x768 recommended)
-
CD-ROM-Drive
-
Hard disk with minimum 30 MB free disk space for program and sample files
-
Microsoft compatible mouse
|
|