Subject: About VAMP: summary

From: "Giulia Caron (la Perla di Losanna)" <[email-masked]>
Date: Wed, 4 Dec 1996 08:06:52 +0000

Thank you very much to people who answered me!
Here is the summary of mails I received!

My original question was

>Dear CCLers,
>
>I like before giving correct assignment to NMR spectra, to have predictions
>of chemical shift by semi empirical methods. VAMP 5.1 (Oxford Molecular)
>uses neural nets to extimate from the wave function the spectroscopic
>properties of molecules but I don't know how it works. 
>Can you help me?
>
>Thank you very much!
>
>                Giulia

Answers
1.
 Dear Giulia, 

How big systems do you want to calculate? 
If it less than 50-80 atoms I would suggest to work with 
Density Functional Theory (DFT) based methods rather than with semiempirical. 
The results normally will be more reliable. 
Please, find below some references.  
Best regards, 
			Vladimir Malkin 

REFERENCES. 

\item {\bf Malkin V.G., Malkina O.L, Eriksson L.A., and Salahub D.R.}
     "The Calculation of NMR and ESR Spectroscopy Parameters Using
      Density Functional Theory", in: "Modern Density Functional Theory:
      A Tool for Chemistry"; Theoretical and Computational Chemistry,
      Vol. 2, Eds. J. M. Seminario, P. Politzer, Elsevier, Amsterdam,
      1995.

\item {\bf Malkin V.G., Malkina O.L., and Salahub D.R.}
     "Calculation of Spin-Spin Coupling Constants Using Density Functional
      Theory", Chem. Phys. Lett. 221 (1994) 91.
 
\item {\bf Malkin V.G., Malkina O.L., Casida M.E., and Salahub D.R.}
     "Nuclear Magnetic Resonance Shielding Tensors Calculated with a
      Sum-Over-States Density Functional Perturbation Theory",
      J. Am. Chem. Soc., 116 (1994) 5898.

\item {\bf Kaupp M., Malkin V.G., Malkina O.L., and Salahub D.R.}
      "Calculation of Ligand NMR-Chemical Shifts in Transition-Metal
       Complexes Using ab Initio Effective-Core Potentials and Density
       Functional Theory.", Chem. Phys. Lett. 235 (1995) 382 .
 
\item {\bf Kaupp M., Malkin V.G., Malkina O.L., and Salahub D.R.}
      "Scalar Relativistic Effects on $^{17}$O NMR Chemical Shifts in
       Transition-Metal Oxo Complexes. An ab Initio-ECP/DFT Study.",
       J. Am. Chem. Soc. 117 (1995) 1851.
 
\item {\bf Malkin V.G., Malkina O.L., and Salahub D.R.}
      "Influence of Intermolecular Interactions on the NMR Shielding
       Tensors in Solid $\alpha$-Glycine.",
       J. Am. Chem. Soc. 117 (1995) 3294.

\item {\bf Woolf T.B., Malkin V.G., Malkina O.L., Salahub D.R., and Roux B.}
      "The Backbone $^{15}$N Chemical Shift Tensor of the Gramicidin Channel:
       A Molecular Dynamics and Density Functional Study", Chem. Phys. Lett.
       239 (1995) 186.
 
\item {\bf Kaupp M., Malkin V.G., Malkina O.L., and Salahub D.R.}
      "Ab Initio ECP/DFT Calculation and Interpretation of Carbon and
       Oxygen NMR Chemical Shift Tensors in Transition-Metal Carbonyl
       Complexes", Chem. Eur. J. 2(1996)24
 
\item {\bf Malkin V.G., Malkina O.L., and Salahub D.R.}
      "Comment on Density Functional Calculation of Nuclear Magnetic
       Resonance Chemical Shifts", J.Chem.Phys. 104(1996)1163

\item {\bf Malkin V.G., Malkina O.L., Steinebrunner G. and Huber H.}
      "Solvent Effect on the NMR Chemical Shieldings in Water Calculated
      by a Combination of Molecular Dynamics and Density Functional Theory",
      Chem. Eur. J. 2(1996)452
 
\item {\bf Fedotov M.A., Malkina O.L. and Malkin V.G.}
      "$^{35/37}$Cl NMR Chemical Shifts and Nuclear Quadrupole Couplings
       for Some Small Chlorine Compounds: Experimental and Theoretical
       Study", Chem. Phys. Lett., 258(1996)330.

\item {\bf Malkin V.G., Malkina O.L., and Salahub D.R.}
      "Spin-Orbit Correction to NMR Shielding Constants From Density
      Functional Theory", Chem. Phys. Lett. 261 (1996), 335.

\item {\bf Godbout N., Malkin V.G., Malkina O.L., and Salahub D.R.}
      "Density Functional Calculations of Deuterium Nuclear Quadrupole
      Coupling Constants", J. Chem. Phys., submitted.
 
\item {\bf Eriksson L.A., Malkin V.G., Malkina O.L., and Salahub D.R.}
      "Investigation of Moessbauer Parameters for a set of Iodine
      Compounds using Gradient Corrected Density Functional Theory",
      Int. J. Quantum Chem., in press.
 
\item {\bf Malkina O.L., Salahub D.R., and Malkin V.G.}
      "NMR Spin-Spin Coupling Constants From Density Functional Theory:
      Problems and Results", J. Chem. Phys., 105 (1996) 8793. 
 
\item {\bf Kaupp M., Malkina O.L., Malkin V.G.}
      "Interpretation of $^{\bf 13}$C NMR Chemical Shifts in Halomethyl
      Cations. A Cautionary Note on the Importance of Spin-Orbit Coupling
      and Electron Correlation", Chem. Phys. Lett., submitted.

 ###############################################################
 #   Dr. Vladimir G. Malkin                                    # 
 #   Senior Research Scientist                                 #
 #   Institute of Inorganic Chemistry                          # 
 #   Slovak Academy of Sciences                                # 
 #   Dubravska cesta 9                [email-masked]          #
 #   SK-84236 Bratislava              Fax    (42-7) 373-541    #
 #   Slovakia                         Phone  (42-7) 378-2923   #
 ###############################################################

2.
Dear Giulia,

you can find all details on the method how Vamp predicts 13C chemical shifts in:

	T.Clark, A.Breindl, G.Rauhut:
	"A Combined semiempirical MO/Neural Net Technique for Estimating 13C
	chemical shifts."
	J. Mol. Model., 1995, 1(1), 22-35.

An abstract can be found at URL:
	http://science.springer.de/jmm/abstracts/1995/clark.html

If you have any questions, problems, suggestions, etc. with Vamp, please have a
look at our WWW page at:
	http://www.ccc.uni-erlangen.de/info/OML/Vamp/

you will find references to the literature, information on coming updates
(version 6.0 should be here for Christmas), and much more.

or just contact the nearest Oxford Molecular helpdesk; for Switzerland that is:
	me.

All the best,

        Wolfgang Sauer
--
PS: Informationen ueber OM finden Sie auch im WWW unter URL:
    http://www.ccc.uni-erlangen.de/info/OML/about-OML_d.html

        Dr. Wolfgang Sauer                    ------------
                                             | ##  ##  ## |
        Oxford Molecular - CCC               |  ## ## ##  |
        Naegelsbachstr. 25                   |   ######   |
        D-91052 ERLANGEN, FRG                |     ##     |
                                             |     ##     |
        Tel : +49 9131 8796 10               |    ####    | 
        Fax : +49 9131 8796 11                ------------

3.
Dear Giulia Caron,

VAMP version 5.6,6.0 and the newest release 6.1 is able to estimate 13C-
chemical shifts via a combination of MO-calculations and a
back-propagation neural network (Lit.: T. Clark, G. Rauhut,A. Breindl
J. Mol. Model.1995,1,22). Originally introduced for neutral organic
compounds, this technique has been expanded to estimate carbocations and
carbanions. VAMP 6.1 is available from Oxford Molecular Ltd.
( http://www.oxmol.co.uk ). 

                                  your sincerely
                                  Andreas Breindl

-- 
Meine Adresse:

Dipl.-Chem. Andreas Breindl
CCC ( Computer Chemie Centrum )
Institut fuer Organische Chemie I der Uni Erlangen-Nuernberg
Naegelsbachstr. 25
D-91052 Erlangen

Tel. 09131-85-6581
e-mail: [email-masked]
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 .---------------------oOOo----(_)----oOOo-----------------------------------.
 | La Perla di Losanna                     | ICT			     |
 | Giulia Caron                            | Section de Pharmacie	     |
 | mail : [email-masked]         | UNIVERSITE DE LAUSANNE          |
 | tel: ++41 21/692-4528                   | BEP CH-1015 Lausanne            |
 | fax  : +41 21/692-4505    Oooo.         |  Switzerland		     |
 |                           (   )   Oooo. |                                 |
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