Subject: TS-search / imag. freq.

From: "Rochus Schmid" <[email-masked]>
Date: Mon, 12 Feb 1996 18:13:16 +0100

Dear netters,

I have a question concerning TS-search and confirmation of it by a vibrational
analysis:

I've located a TS (DGauss 3.0, LDA-level, DZVP Basis) by EF with the
convergence criterion of the max. component of the (cartesian) gradient vector
to be less than 0.0008 au (which is the default in Dgauss as suggested by
Andzelm for the DZVP-level).

The mass weigthed Hessian matrix (2nd derivs. calculated analytically) shows
three imag. frequencies. One is large (700 1/cm) and the other two are small
(less than 50 1/cm). These two and four other small, but real frequencies
should represent the six degrees of rotation and translation which are not zero
since I'm not exactly at the stationary point. Correct?

After projecting out these six degrees of freedom only one neg. frequency
remains (about 700 1/cm).

Can I trust in that?
Or is it necessery to tighten the convergence criterion?
What is your experience?

Every comment or advise is highly appreciated. Thanx in advance.
(I will summarize.)

Greetings from Munich to all of you,

Rochus

-- 

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Rochus Schmid
Technische Universitaet Muenchen	Tel. 	++49 89 3209 3140
Anorganisch Chemisches Institut 1	Fax. 	++49 89 3209 3473
Prof. W. A. Herrmann			E-mail:	
Lichtenbergstrasse 4			[email-masked]
85747 Garching
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