Utility mpp - Version 1.0
Dear netters,
First let me wish everyone a merry christmas and a happy new year.
Second I would like to present a small utility to the net, that might be
usefull to everyone who works with mopac.
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Mopac - Preprocessor (mpp) Version 1.0
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Molecular geometries can be defined in several ways, for example by using
cartesian coordinates or by using internal coordinates. The last possibilty
is used in the case of the well-known Z-matrix.
One of the major disadvantages of using the conventional Z-matrix as an input
for Mopac-calculations is the difficulty in keeping track of the numbering of
used atoms. This can get quite tricky in the case of very large molecules.
Another problem frequently encountered in the construction of a Z-matrix is,
if one wants to substitute the functional groups of a molecule by other
substituents.
The program mpp enables the construction of a Z-matrix in a different
and new way. The molecule is splitted in smaller fragments, so that a
Z-matrix can be constructed without much efforts, and subsequently defining
the location of a fragment relative to another.
The benefits of the above method are:
o The construction of a Z-matrix, even for larger molecules, is much easier
without having to resort to computer programs like PC-model.
o Substituting fragments of a molecule with different fragments, does not
require a recalculation of the referenced atom numbers.
o By using an archive of fragments, it is not necessary to reconstruct
frequently used fragments again and again. (e.g. Methyl- or
phenylgroups)
Another case where the new method is useful, is when one wants to look at the
interaction of two or more molecules.
I you want to use this program let me know by E-Mail and I will send it to you.
Peter Gedeck
Inst.f.Phys.Chem. I
Egerlandstrasse 3
8520 Erlangen
Germany
gedeck %-% at %-% pctc.chemie.uni-erlangen.de
++49-9131-85 7335