DisFact system is an unique instrument for structural research. It allows to get quantitative evaluation of asymmetry and chirality of molecules of any structural types. The specified information can be useful at the solving of various structure - property tasks as well as in education.

The cut free version is available on the following site:
(self-extractor of installation files, for x86 and WIN32s or WIN32, ~ 850Kb) - disfact.exe or disfact.exe.
It incudes all functions of whole DisFact system but can calculate structures with 12 points (atoms) maximum. The on-line Help (by pressing F1 key) is designed for covering most of your questions.

If you want to calculate your larger rasks, please e-mail to theochem@narod.ru

Copyright © by: Theoretical Chemistry Team of A. V. Bogatsky Physical-Chemical Institute of the National Academy of Science of Ukraine

Technicality

The entrance information:
a) spatial structure of molecules as files of several popular formats;
b) list of symmetry elements (in range C2-C20 and S1-S20) and/or overall chirality symbol ('EDF') and other adjust parameters for calculation.

The target information:
a) quantitative evaluation of molecular chirality and/or asymmetry;
b) image of molecule and of best found orientation of symmetry element, and, additionally, of molecule's main inertia axes and initial crossbar system.

DisFact system realizes the folding-unfolding, the optimized Dissymmetry Function (Asymmetry Function), and the "EDF" (Enantiomer Dissimilarity Factor) methods.

References

"folding-unfolding" method:
Zabrodsky, H.; Peleg, S.; Avnir, D. Continuous Symmetry Measures. J. Am. Chem. Soc. 1992, 114, 7843-7851;
Alikhanidi, S. E.; Kuz’min, V. E. An Optimization of Asymmetry Evaluation of Molecules within the Bounds of Folding-Unfolding Method. J. Mol. Mod. 1999, 5, 116-124;

Dissymmetry Function method:
Kuz'min, V. E.; Stel'makh, I. B.; Bekker, M. B.; Pozigun D. V. Quantitative Aspects of Chirality. I. Dissymmetry Function. J. Phys. Org. Chem. 1992, 5, 295-298.

Asymmetry Function method:
Alikhanid, S. E.; Kuz'min, V. E. An Optimization of Quantitative Asymmetry Evaluation of Molecules within the Bounds of Dissymmetry Function Method. Zh. Struct. Khim.., 2000, 4, 795 - 804 (in Russian).

EDF method:
Alikhanidi, S. E.; Kuz'min, V. E. Quantitative Evaluation of Molecular Chirality on Base of an Optimized Approach to Original and Reflected Structures Comparison. Reports of NAS of Ukraine, 1999, 3, 138-141.

Application for QSPR ("Structure - Property") tasks:
Alikhanidi, S. E.; Kuz’min, V. E.; Kutulya, L. A. On Relationship between Helical Twisting Power of Chiral Dopants in Induced Cholesteric Mesophase and Their Chirality Parameters. Functional Materials. 1999, 4, 710 - 714.

Alikhanidi, S.; Kuz’min, V. Stereodesign of chiral para-substituted calix[4]arenes. J. Mol. Model. 2001, 5, 143 - 146.