Subject: CBS and properties

From: [email-masked] (Dave Young)
Date: Wed, 10 May 95 08:32:16 -0400

Hello,

	I have been reading the complete basis set papers which were 
referenced on this list last week.  It looks like an interesting technique 
so I'll have to try it.

  	What I am wondering about is the possibility of getting properties
such as dipole moments and electrostatic potentials more accurately in
a similar manner.  

	My initial response is to say that a simplistic method which 
defines energy as a linear combination of energies from multiple
calculations could easily predict a dipole with the same linear 
combinations of dipoles.  However, a method with many complex integrals 
in the extrapolation proceedure might present technical difficulties for 
the extrapolation of properties.

	I would like to hear comments on the feasibility of extrapolating
property values.  If there are any references to methods for doing this,
please send them to me.

				Dave Young
				[email-masked]

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	In conventional ab initio calculations, an initial calculation
is done using the central field approximation.  Then a second calculation
is done to eliminate the errors introduced by that approximation.  Often
more time is spent correcting for errors in the original calculation
than on the original calculation.
	Why not just avoid making those errors in the first place?
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