Subject: Simulation of infra-red spectra.

From: Dave <[email-masked]>
Date: Thu, 18 Nov 1993 10:06:23 GMT

I am currently involved in a project which is trying to develop 
polymers with very specific infra-red characteristics. We will be 
attempting to speed up the development of the materials by using 
spectral simulation methods to 'test-out' proposed monomer units 
or 'model systems' to see if they meet the specifications that we have 
been given by our sponsors.

We have an SG Indy on which we will be running POLYGRAF by MSI. 
As far as I am aware this software uses MM methods for the 
simulation of the spectra. I am however, doubtful of whether or not the 
 vibrational analysis routines on this program will give sufficiently 
accurate IR spectra. Obviously Semi-emprical or ab-initio MO 
calculations (which it is conceivable that we may run on a Cray) will 
be more accurate but this is at the expense of being much more 
computationally intensive. It is also not clear to me just how much 
more useful, spectra calculated by Semi-empirical or ab-initio 
methods would be.

Has anybody any experience in such work? If so I would be very 
interested to receive any advice regarding the pro's and cons of the 
various methods which are available.

I look forward to hearing from you in the near future.

Kind regards in advance 

Dave Tilbrook
Has anybody 
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David Tilbrook              *   Tel: 44 483 300 800 x 2632
Polymer Group,              *                       x 2617
Chemistry Department,       *
University of Surrey,       *   Fax: 44 483 300 803
Guildford, Surrey, GU2 5XH  *
U.K.                        *
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