Operating instructions for the Group Theory Calculator

The Group Theory Calculator [the GT Calculator] is the set of interactive EXCEL spreadsheet files, one for each of the main molecular point groups, on the CDROM supplied with this manual. The group theoretical calculations, which can be performed with the calculator, are rendered possible because of the enhancement of the basic spreadsheet operations and displays using Visual Basic for Applications code and the complex-arithmetic routines available in the Analysis Tool Pack EXCEL Add-ins . Since the Analysis Tool Pack is not one of the standard components loaded in a typical installation of the EXCEL software package, it is necessary, before attempting to use the GT Calculator, to ensure that your version of the EXCEL programme includes this extra component. With any spreadsheet open, check the Add-ins list in the TOOLS menu on the main EXCEL toolbar and, if necessary, install this component in the usual way. 

It is advisable to open and use only one EXCEL file and, especially, not to have blank new spreadsheets open at the same time. While the default exit procedure in the VBA code involves the instruction Application.quif, on occasions the presence of another open workbook can interfere with the closing sequence. 

With the GT Calculator you can perform a variety of standard group theory calculations simply by entering the appropriate structure details for the molecular geometry. In addition, on the various worksheets of the calculator files, it is straightforward to determine more advanced group theoretical results, such as the numbers of isomers generated for a given structure by decoration, or to calculate and decompose the symmetric and antisymmetric powers of permutation representations. 

If such matters are familiar and you are comfortable with the concepts of Group Theory on the Spherical Shell, it is probably necessary only to read through the operating instructions in the remainder of this chapter before using the calculator files for your own group theory analyses. Otherwise, you are advised to study the material in the remaining chapters prior to any extensive use of the calculator. 

In the second screen dump, the contents of the icosahedral folder is displayed and, as you see, this folder contains EXCEL files for the two point groups, I and Ih, of icosahedral symmetry. 

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