Subject: freezing heavy atoms, unfreezing hydrogens

From: Jana Precechtelova <[email-masked]>
Date: Thu, 31 Oct 2002 18:02:28 +0100 (MET)

I`d like to perform a geometry optimization (in Gaussian) of a molecule
defined by cartesian coordinates. During the optimization, I need to
freeze heavy atoms but let hydrogens to be optimized. How can I easily
achieve this? I`ve already tried it using a ModRedundant option to the
Opt keyword and by specifying atoms to be fixed via this sequence:
X N F (N is a number of atom) but this attempt failed.

Best regards,
Jana Precechtelova

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Jana Precechtelova
National Centre for Biomolecular Research (NCBR)
Faculty of Science
Masaryk University
Kotlarska 2                                email: [email-masked]
611 37 Brno                                         phone: +420-5-41129588
The Czech Republic                                  fax: +420-5-411 29 506
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