Subject: 2 electron problem: full CI

From: Wolfram Koch <[email-masked]>
Date: Tue, 19 Nov 1996 15:20:44 +0100 (NFT)

Hi everyone,
I am facing a problem that is difficult because it is too easy ;-)
We are considering to  enter a project for which we require as
accurate as possible information about the potential curves of a
large variety of excited states of the He2(++) dimer. This is a 2 
electron system and one is tempted to employ methods such as 
Hylleras CI or some variant thereof (i.e. wave functions 
that explicitly contain the e-e distance).
Can anyone give us a hint who might have such a piece of software and
would be willing to share it with us? Also, more general comments on how
to deal with two electron problems are welcome. Doing a full CI with a
general purpose program is probably not the smartest thing to do.
I know that there are of course a lot of calc's on the He2(++) ground 
state (after all, it is a metastable, experimentally well established 
molecule!) but I am not aware of too many studies considering excited states. 
But this could well be due to the fact that I am not following the
physics literature as closely as I should. Should you know of 
any recent and good investigation on that subject that might have  
escaped my attention, pls. let me know as well.
Many thanks in advance.

Wolfram
-- 
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 Prof. Dr. Wolfram Koch     Institut fuer Organische Chemie, Sekr.C3
                            Technische Universitaet Berlin
                            Strasse des 17.Juni 135, D-10623 Berlin
                            Fon: +49 30 314 27870, Fax: +49 30 314 21102
                            e-mail: [email-masked]
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