Subject: CCL:Getting electronic spectrum info from Gaussian

From: "Jens Spanget-Larsen" <[email-masked]>
Date: Wed, 30 Oct 2002 10:36:15 +0100

John McKelvey:

> For organic systems the most reliable way in Gaussian is to optimize
> the geometry with something like B3LYP/6-31G*, and then do ZINDO
> with all single excitations.  Use of semi empirical geometries
> should be used with the utmost caution, particularly if molecules
> are non-planar... they are "cheap," but....

I agree with John. - If you are willing to spend more CPU time, you 
may consider time-dependent density functional theory, f.inst. at 
the TD-B3LYP/6-31G* level. Juergen Fabian recently published a survey 
of electronic transitions predicted with TD-B3LYP, ZINDO, and PPP for 
a large number of sulfur-organic compounds -

J. Fabian: "Electronic excitation of sulfur-organic compounds - 
performance of time-dependent density funcyional theory", Theor. 
Chem. Acc. 106, 199-217 (2001).

Yours, Jens >--<

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From: [email-masked]
Date: Wed, 30 Oct 2002 09:00:20 +0000

OOPS,

I left out P.J. Hay and Richard L Martin

John

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From: [email-masked]
Date: Wed, 30 Oct 2002 08:58:51 +0000

A further comment:

If you want to hear the latest on computing spectra usung the latest
ab-initio based methods, namely TDDFT, and related methods, you are urged
to attend the symposium on this at the New Orleans ACS meeting March
23-27, 2003.  Geometries of excited states using TDDFT will also be
discussed.

Speakers:

E. J. Baerands
Mark Casida
Ken Wiberg
John Jean
Filipp Furche
Tom Ziegler
Jochen Autschbach
Martin Head-Gordon
Frank Neese
Stefan Grimme
Kieron Burke
Mel Levy
Weito Yang
Serg Tretiak
Gary Trucks
Rod Bartlett

Regards,

John McKelvey
Kieron Burke