Subject: Summary CCL: Vibrational spectra.

From: Sergiusz Kwasniewski <[email-masked]>
Date: Wed, 6 Jan 1999 11:55:54 +0100 (MET)

Thank you for your responses. Or should I say "dziekuje bardzo". As it is
custom to make a summary of all the responses, I will serve you the
following emails:

S. Kwasniewski

++++++++++++++++
(original email)
++++++++++++++++

Does anyone know how to calculate excitation spectra ? And what kind of
program would you prefer ? We've been using MOPAC here (semi-empirical
techniques) to run MECI calculations. In the end we want to be able to
calculate UV/Vis absorption spectra.

We were also thinking about buying Hyperchem (if there are versions for
workstations available that is). I think I read somewhere that the
calculations of certain spectra is included in this.

Does anyone has another suggestion for programs/methods to use, or some
pros/contras on MOPAC and Hyperchem ?

Thank you.

S. Kwasniewski

+++++++++++++++
(first respons)
+++++++++++++++

Sergiusz,

    ZINDO and Argus have been parameterized explicitly to do
UV/visible spectra.  ZINDO may be available from the Quantum
Theory Project at the University of Florida, the home of Michael
Zerner, its author.  It is available commercially from Molecular
Simulations (www.msi.com)

    Argus is free and is available at
http://www.seanet.com/~mthompson/ArgusLab/index.htm

Best wishes,
Paul Soper
DuPont Central Research & Development
Wilmington, DE  19880-0328 USA

DuPont Central Research & Development
Wilmington, DE  19880-0328 USA

++++++++++++++++
(second respons)
++++++++++++++++

Dear Sergiusz,

    In my experience calculations of electronic excitacitions using
AM1/PM3
produce results that are in disagreement with experimental results. The
positions of the transitions are OK, but the orbitals involved in that
transitions
are assigned in a very strange manner. For a reference look:

        Spectrochimica Acta A, 54, 339-348 (1998).

    In this work we conclude that the best method for calculations of
electronic
spectra of organic compounds, with small computational resources, is
INDO1/S. A version of this method is available free in the net, the
ArgusLab
program at:

http://www.seanet.com/~mthompson/ArgusLab/index.htm

    Best regards,

                Sergio ([email-masked])

+++++++++++++++
(third respons)
+++++++++++++++

I would advise against mopac.  Traditional semiempirical methods are not
advisable for excited state calculations.  I would advise using ZINDO
which is a CIS method derived from MOPAC.

Deepak Singh                            Email: [email-masked]
Graduate Fellow                         URL: http://web.syr.edu/~desingh
Department of Chemistry and Biochemistry,       Tel: (315) 443 1739 --
work
Syracuse University                            (315) 472 9659 -- home
1-014 Scitech Syracuse NY 13244         Fax: (315) 443 4070

"Violence is the last resort of the incompetent". -- Salvor Hardin

++++++++++++++++
(fourth respons)
++++++++++++++++

    My advice is to use HyperChem. The version 4.5 for SGI (and
probably for other machines) can be downloaded for testing and a
trial licence is valid for a month.

    Sam skorzystalem z tej mozliwosci. Uzyskalem dosc dobra zgodnosc
obliczonych i wyznaczonych spektrow. Ale optymalizacje struktur
prosze zrobic programem z opcja ab initio. Opcja ZINDO nie nadaje sie
do tego.
    If you understand the above, Good luck!

    S.Kucharski

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* Institute of Organic and Polymer Technology                       *
* Wroclaw Technical University                                      *
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+++++++++++++++
(fifth respons)
+++++++++++++++

Hi,

ZINDO is a semi-empirical package specially designed to calculate spectra.
This program is from Dr. Zerner.

Yongxing Liu

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Sergiusz P. Kwasniewski

Limburgs Universitair Centrum
Universitaire Campus, Gebouw D
3590 Diepenbeek
Belgium
Tel. (+32) (0)11/26.83.15
Fax. (+32) (0)11/26.83.01

e-mail: [email-masked]

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