TS-search / imag. freq.

["Rochus Schmid" <rochus -8 at 8- felix.anorg.chemie.tu-muenchen.de>]

 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			rochus -8 at 8- felix.anorg.chemie.tu-muenchen.de
 85747 Garching
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