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Current status and development history of ObjCryst++

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Current Status

The Library is moving along beta stage. The interface has been changed to a better design, especially for the scattering/diffraction class. The RefinableObj is also being improved to be more 'generic' and easier to use with varied algorithms.
Spacegroup
Thanks to the sglite package, all SpaceGroup can be recognized from their symbol. An AsymmetricUnit is also generated for each spacegroup (actually it is a parallelepipedic approximation). Only 3D spacegroup are allowed. We will eventually (that is, when I find time... at the autumn 2001, move to the cctbx library
Crystal
For a Crystal, definition of spacegroup and adding of various types of scatterers are working. Dynamical occupancy correction for global optimizations has been implemeted (to correct overlap of identical atoms due to sharing of corner atoms in polyhedra, or due to symmetry). An anti-bump cost function (simple) is also implemented, and also enables atoms to merge continuously. An output to povray file is provided, as well as an OpenGL display of the cystal structure (only tested using Mesa under linux, with glut). Most important lacking features are saving structure to CIF files.
Scatterer
Various type of Scatterer are provided : simple Atom but also ZScatterer, using a Z-Matrix Description, and derived form it are ZPolyedron (tetrahedron...icosahedron..). other types of scatterer can easily be added. So far the scattering power and thermic factor must be isotropic. Scattering factors for X-Rays (Thomson using the interpolated values and resonant (anomalous using either Sasaki or Henke tables) and neutrons are provided.
ScatteringData
PowderPattern is the most developped class and its support is sufficient for most Global Optimization work. DiffractionDataSingleCrystal is less being worked on, but it can be used provided that the data has been corrected and merged beforehand.
Global optimization
GlobalOptimObj provides an algorithm for the so-called 'ab initio' structure determination from diffraction data using either a simulated annealing or a parallel tempering algorithm. Genetic algorithm may be added later.
Least Squares
LSQObjNum class provides a rough least squares support, but it is definitely not the purpose (as of yet, at least) of this library. The most important lack is that numerical derivatives are systematicllay used. I wrote this only for testing purposes and have not sed it for some time, so try it at your own risk !
Graphical user interface
Most objects have a graphical counterpart, which has been created using the wxWindows (linux,unix,windows,mac,...) library. The result is the Fox program, but the GUI interface can be used for any other purpose. It is of course possible to use ObjCryst++ without the wxObjCryst part.

History

1.0(2001-??)
0.9.1(2001-09-20-)
0.9(2001-09-18-first FOX Release)
0.5(july 2001)
0.6(march 2001)
First public release.
0.5 (february, 2001):
0.4 (january 2001):
0.3 (2000, november 24) :
0.2 (2000, november 07) :
0.1 :

Generated on Wed Nov 14 19:48:36 2001 for ObjCryst++ by doxygen1.2.11.1 written by Dimitri van Heesch, © 1997-2001