From chemistry-request@ccl.net Fri Apr 24 16:30:45 1992 Date: 24 Apr 92 14:13:48 GMT From: Siegfried.Schneider@CNVE.RRZE.uni-erlangen.de To: CHEMISTRY@ccl.net Status: RO I developed a program, which might be of interest for those who prefer to write there Z-matrices by hand. One of the mayor disadvantages of using a conventional Z-matrix as an input for Mopac-calculations is the necessity to keep track of the numbering of the used atoms. This can get quite tricky in case of very large molecules. Another problem frequently encountered is if one wants to substitute parts of a molecule by other substituents. The program enables the user to split a molecule into fragments, defining the Z-matrix for each fragment separately and putting fragments together by defining postions of a fragment relative to another fragment. (Hope everyone understands what I mean) Also it is possible to use an archive of fragments, so that frequently used groups (e.g. methyl of phenyl) can be incorporated easily. Another application would be the study of a complex of two molecules or a molecule surrounded by a solvent. The benefits of the program are: o The construction of a Z-matrix even for larger molecules is much easier, without recoursing to computer programs like PC-model. o Substituting fragments of a molecule by different fragments, does not require a recalculation of the referenced atomsnumbers. Also the atoms of a fragment are not spread over the whole input-file. o By using an archive of fragments, it is not necessary to reconstruct frequently needed fragments again and again. (e.g. Methyl- or phenylgroups) The program is written in C and was tested on a PC an a workstation. Whoever is interested in this program can get it from me. Just send a letter and I will post the source-code. Peter Gedeck Peter Gedeck Inst.f.Phys.Chem. 1 Egerlandstr. 3 8520 Erlangen FAX 09131 - 858307 E-mail : PC1@cnve.rrze.uni-erlangen.dbp.de