The program MolSym provides teachers, students and researchers with tools for dealing with diverse aspects of symmetry point group theory and applying them to specific examples and problems. The program can be used for professional or didactic purposes, by teachers or students. Below you can see typical aspects of the program in work (click over the figures to amplify them).

Molecular symmetry has become a traditional theme in structural chemistry due to its practical relevance to many other fields, such as quantum chemistry, force field analysis and spectroscopy, among others. Although the concepts related to molecular symmetry are not particularly complex, their rigorous application often requires the use of a mathematical formalism known as "point group theory".

Main topics covered 
 

• symmetry elements
• symmetry operations
• group properties
• operation matrices
• character tables
• molecular structure
• atom permutations and equivalences
• deduction of symmetry
• construction of symmetrical structures

• High resolution graphics shows atoms, bonds, axes, center, planes, in various display modes. Objects in drawings can act as hot links to small informative dialogs, for example, clicking on a symmetry axis would display the symbol of the axis and its direction vector.

 
• Extensive data tables, displayed as scrolling listboxes.

 
• Drawings and data tables can be viewed simultaneously in a correlated way (for example, selecting a symmetry element in the "Symmetry Elements" listing (a table) will immediately highlight the element in the drawing.

 
• Commands to open, save, rename, import and export problems as single files.

 
• Edition and/or generation of any molecule. Of particular interest is the program ability to build symmetrical molecules from "seed atoms". A built-in isotope table simplifies atom selection

 
• Constructing any symmetry group "ex novo", or deducing the symmetry group of an existing molecule.

 
• Translations and rotations of a molecule with respect to the world coordinate system, through motion commands which include instructions to easily achieve special orientations.

 
• Printing separately what you need: graphics or selected tables.

 
• Extensive context-sensitive on-line help, accesible also by contents, keywords or word searching. A glossary of concepts used by the program is included.

 
• Tutorials: From the on-line book "Tutorials" you can consult 5 comprehensive tutorials which illustrate the use of the program.

 
• Samples: an initial set of problems will be helpful to the user to become familiar with the program.

 
• Automatic installation and unistallation procedures are included.

 

Applications of MolSym 3.0 

The program MolSym can be of interest for two kinds of people; those specifically interested in symmetry by achademic reasons, as teachers and students; and more generally chemists and researchers working with symmetrical molecules. The former will find in the program tools for rapid generation or revision of examples and illustrations. Information which normally requires consulting books, as the character table of a group, can be retrieved in seconds by using the program. An example of program usage by a researched could be the construction of complex symmetrical structures from a few input atoms. The resulting coordinates might be input to another program, perhaps a quantum chemistry program. 

Requirements 
 

• Windows 95 or Windows NT (MolSym is a 32-bit program)
• Hard disk, color monitor, mouse, keyboard.

Download 

There is avalilable a shareware version: this is a free fully functional evaluation version. You can freely use, copy or redistribute (in its entirety) the shareware version. You should read the more detailed use and redistribution conditions explained in topic "Shareware version" from the installed program.

History 

The antecessor of MolSym 3.0 for Windows was MolSym for DOS. The current Windows version took much benefit from the experience gained with previous versions. New capabilities have beed added, and you can now enjoy the convenience of Windows environments. Many limitations inherent to DOS environment disappeared naturally in the version for Windows. It is my aim to continue offering efficient state-of-the-art software architecture products to the scientific community. 

Author 

Luis Vazquez-Vidal, the author of Molsym, deceased 1998