Help fight Software Patents !
You who enjoy the use of free software, please take some
time to think about Software Patents! If these are made legal in Europe
too, that could eventually lead to the extinction of free software. Please
see more information on the main ObjCryst++/Fox
web page (UK,
Canada,
US Mirror)
for a scientific approach of the problem, and on FFII
and EuroLinux.
I will not be able to distribute Fox anymore if/when
Software Patents exist in Europe...
Author: Vincent
Favre-Nicolin (http://v.favrenicolin.free.fr
)
This program was developped in collaboration with Radovan
Cerny, and was written at the Laboratory
of Crystallography, in Geneva (Switzerland), with support from the
Swiss National Science Foundation.
(project #21-53847.98)). The development still goes on as a personal research
project after my move to the ESRF.
See the ObjCryst++ homepage for more details about the source code.
Reference for Fox
The reference for Fox is: V.Favre-Nicolin and R. Cerny, J. Appl.
Cryst (2002, accepted), http://objcryst.sourceforge.net.
NEWS
Latest version is 1.2 (july 2002). It adds the ability to analyze data with preferred orientation (texture, searching ab initio the texture parameters), using the March-Dollase model. The 'live' update of the 3D view of the Crystal structure now also works on all windows versions. See the full changelog.
The FOX program was made for the ab initio structure solution from powder diffraction data. Its most interesting features for ab initio structure determination are :DownloadSo, if you have:
- the ability to use multiple patterns (X-rays, neutrons), as well as single crystal data (eg extracted from a powder pattern)
- a versatile description of scatterers: either isolated atoms , molecules described using a bond length, bond angles and dihedral angles, and polyhedra for inorganic compounds. You can describe your structure by using any combination of groups of atoms, using a chemist's or crystallographer knowledge about the connectivity in your sample .
- An automatic and dynamic correction for special positions and shared atoms between polyhedra, suitable for a global optimization algorithms.
- Global optimization algorithms which can get out of false minima.
- A graphical interface with a 3D crystal structure view, live updated during the optimization process.
Then Fox can help you.
- have an unknown compound but with (approximately) known composition.
- have a powder pattern (X-Ray or Neutron or both), which you have already indexed (with the refined unit cell), and for which you have some idea of the possible spacegroup(s) (using systematic extinctions).
- would like to solve the structure (ie find the atom -or group of atoms- positions, before refining them with another package).
This program can be used also for educational purposes , to show a 3D display of Crystal structures, and the associated powder pattern(s) (see how adding atoms, changing the lattice, or changing the spacegroup affects the powder spectrum and the 3D structure).
If you would also like to choose your own criterion and algorithm to solve the structure, then it will be even better : FOX is built on a very customizable and expandable library, which allows you to evaluate your Crystal structure following a combination of criteria: currently there are only R, Rw factors and an Anti-bump cost function, but it would be very easy to write a new criterion using (say) interatomic distances (energy of the configuration, analysis of the coordination). This, with a versatile way to describe the unit cell's contents, is what makes the algorithms used interesting.
For example you can combine several Powder patterns (X-Ray, Neutron,...) for the same structure,...
FOX is available in precompiled form or as source code for Windows (tested on 98, NT4 SP4, 2000) and Linux. You can download from several sites: For Windows, download the Fox-date.zip file (precompiled), or the Fox-date-src.zip (as source code).InstallationFor Linux, download the Fox-date.tar.bz2 (source code).
Please send me an email. to tell me if you have trouble with the linux install.
Note2: This is an open-source project. If there is something that you would like to see in it, you can contribute to it by submitting code. See the ObjCryst++/FOX Web Site for details.
Note3: if the program encounters an error, it will sometime manage to save the complete environment in a file which should be where you launched Fox (or in your home directory under Linux, or along the Fox.exe application under windows), named "ObjCryst-date-time.xml", which you can then reload.
The FOX Program is copyright (2000-2002) Vincent FAVRE-NICOLIN, (2000-2001) Radovan CERNY, and (200-2001) the University of Geneva.This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
It also uses other libraries (among which R. Grosse-Kunstleve library used to interpret spacegroup symbols), see the corresponding ObjCryst++ page for details.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
This page & project is hosted on
and mirrored on CCP14 ( UK mirror, Canadian Mirror, US Mirror, Australian mirror)