Subject: Spartan and Z-matrix

From: [email-masked] (Chun Yang)
Date: Sat, 30 Sep 95 09:28:22 PDT

The default optimization method in Gaussian 94 
is the redundant geometry optimization.  You can
use Cartesian, Z-matrix or mixed coordinate in
the input, However, if you use the default optimization 
keyword, Gaussian will direct it to the redundant
geometry optimization.

In acyclic molecules, its worst performance is about the same
as Z-matrix.  In cyclic molecules, its performance
is much better than Z-matrix.  So that's why Gaussian
use it as a default optimization method.  One of
the references is:

 CY Peng, Schlegel HB., Isr. Journal of Chemistry,
33(4):449-454, 1993
   You can also see some of Baker's papers.

ChunYang Peng

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