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Date: Tue, 21 Feb 95 20:04:02 +0100
From: lnl@novo.dk (Leif Norskov)
Message-Id: <9502211904.AA24570@bisse.novo.dk>
To: chemistry@ccl.net
Subject: Re: conformational isomers



Dongchul Lim (lim@rani.chem.yale.edu) asked

  > Is there a simple way of testing if two given conformational isomers
  > are equivalent?
  > E.g., how can you know the gauche (+) conformer of n-butane is
  > equivalent to the gauche (-) conformer?
  > My idea is [ to superimpose the conformers ]...


If speed is a problem (and it could well be - consider for example
the matching of the protons in butane) then it might be advantageous
to first compare the moments of inertia, which of course are invariant
to atom labelling and rotation/translation, before proceeding
with superpositioning.


Cheers,

Leif Norskov
Novo Nordisk A/S
Copenhagen
Denmark
lnl@novo.dk