Subject: iron basis set

From: [email-masked] (Dr.Pierre Acklin)
Date: Tue, 4 Oct 94 12:02:02 +0100

Dear Netters,

	I am trying to model iron complexes with round about 30 
heavy atoms. Introducing special angular and torsional constraints
into amber force field calculation in MacroModel leads to good 
and reproducable geometry predictions. 
	Geometry predictions are ok as they allow to discriminate 
between molecules which can form chelate complexes and those, which 
can't. Nevertheless it would be very helpful for the project, if 
some kind of energy or stability predictions would be possible.
This makes me ask you the following questions:

Is it possible to treat iron complexes with more than 30 heavy
atoms in an ab initio program like Gaussian in a reasonable time
on a SGI workstation?

Are there any basis sets and references therefore available to
handel iron in Gaussian92 or DFT on a better level than sto-3g?

How good are results of semi empirical calculations form Ampac 
or Zindo in terrms of energy and geometry?

I'll be glad to summarise the responses for the list.

Pierre
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Dr.Pierre Acklin
CIBA-GEIGY AG
K-136.P.13
CH-4002 Basel         [email-masked]
++41 61 696 23 62
++41 61 696 23 75
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