Subject: Re: CCL:opt=z-matrix

From: Christoph Maerker <[email-masked]>
Date: Mon, 31 May 1999 12:44:22 +0200 (MEST)

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Dear Lars,

you wrote:

>I am performing geometry optimizations using Gaussian98 using
>opt=z-matrix. My problem is that every time an angle reaches a value
>larger than 180 degrees, the calculations stops. Is there a way of
>avoiding this.

There are, indeed, several strategies to avoid such errors. 

1) Write a correct z-matrix is the best solution. I guess you have to include
an additional dummy atom.
2) Use another coordinate set, e.g. internal redundant coordinates (highly
recommended) or cartesians.

Regards,
Christoph