Subject: Re: CCL:M:Constraints in MOPAC

From: Jeffrey J Gosper <[email-masked]>
Date: Thu, 20 Feb 1997 10:02:18 GMT

On Wed, 19 Feb 1997 15:52:02 -0500 David Bevan wrote:

> From: David Bevan <[email-masked]>
> Date: Wed, 19 Feb 1997 15:52:02 -0500
> Subject: CCL:M:Constraints in MOPAC
> To: [email-masked]
> 
> How does one constrain a dihedral angle during geometry optimization in
> MOPAC 93? I am aware of PATH calculations in which a dihedral can be
> changed and the geometry optimized at intervals of the reaction 
coordinate.
> Is there a way to constrain a dihedral when not doing PATH calculations? 
If
> so, is there a way to change the value of the constraining force?
> 
> David Bevan
> 

An optimization flag of 0 will maintain that particular variable. If all 
others have 1 flagged then you'll get selctive optimization.

see http://www.brunel.ac.uk/depts/chem/ch241s/re_view/irc.htm for further 
details on MOPAC input files.

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 Dr. Jeff Gosper                                         
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