Subject: Re: CCL:question on irc

From: [email-masked] (Han Zuilhof)
Date: Fri, 09 Jan 1998 08:24:38 +0100

At 8:29 PM 1/8/98, Armando Juan Navarro Vazquez wrote:
>Dear netters:
>I have tried to perform a irc calculation on a system with a very flat
>potential surface, but it could be only completed sucessfully on one side
>of the potential, but only one point is located in the other side (program
>considers is as a minimum). How can I calculate further points on this
>side of the potential?.
>Thanks in advance
>  Armando Navarro
>  Departamento de quimica Organica. Facultade de quimica. Universidade de
>  Santiago de Compostela.
>  e-mail:[email-masked]
>
Dear Armando,

Try bigger step size.  This often helps to find points on the reaction
coordinate which are indeed lower in energy than the TS;  once you're going
downhill, further IRC following becomes easier.  I've bumbed into this
situations myself several times, and this was the solution to at least my
problems.  Don't make the stepsize TOO big, as this might mean that you
lose track of the IRC, and start to wander about on the potential energy
surface.

Finally, several questions and answers on problems with IRC are available
in the CCL archives, which -with the new web search engine- is a really
easy to use tool.

Best regards,
Han

______________________________________________________________________
Han Zuilhof                         |  E-mail:  [email-masked]
Laboratory of Organic Chemistry     |  FAX   :  31-317-484914
Department of Biomolecular Sciences |  phone :  31-317-482367
Wageningen Agricultural University  |
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