Subject: Summary : ab initio NMR calculation (paramegnetic system)

From: Alessandra Villa <[email-masked]>
Date: Thu, 21 Jan 1999 17:13:15 -0800

I thank you all the persons that answer me and try to help me
I summary the answers (4) , maybe it could be halpfull some someone else.
Best Regards 
                      Alessandra

Questions:
> 
> Dear All, 
>        
>         I wonder if someone have performed ab initio NMR
> shielding tensor calculations on paramagnetic compounds by means of GIAO
> or CSGT methods. 
>        Could you point me some paper concerning the argument? or could you
> write me your knowledge about the reliability of GIAO and CSGT NMR
> shielding tensor calculations on paramagnetic molecules? 
>        I will summary all the answers.
>        Thank you 
> 
>  Alessandra  

Answers:

*****************************************************************************
From: "Y. Tantirungrotechai"

You might like to ask Dr. K. Ruud who implement GIAO in Dalton. 
 
I asked to Dr. K. Ruud, follow his answer
From:Kenneth Ruud

 As far as I know from reading about the NMR of
paramagnetic molecules, there are no problem in calculating the
NMR parameters of such compounds. There might be important higher-order
contributions from e.g.spin-orbit coupling. However, these may aso be
calculated with e.g. Dalton.
The main problem is normally that programs cannot easily or accurate treat
open-shell systems. Dalton should be able to do a fair job on these
systems.

*****************************************************************************
From: Georg Schreckenbach

I have read statements like "truly
quantitative calculations of chemical shifts for paramagnetic compounds
have not yet been reported" (B=FChl et al., J. Comp. Chem. 1999, 20, 91) whi=
ch supports this view. 

*****************************************************************************

From: Douglas J. Fox

  Cheeseman, et. al. looked at this when implementing the procedures for
Gaussian94.  J. Chem. Phys. vol 104, pp 5497 (1996).
*****************************************************************************

From:Noah W. Allen, III

You might want to check a review article by A.C. de Dios found in the
"Journal of Progess in NMR Spectroscopy", 82 (1985) 5035.  It's an excellent
source of review for this material.

*******************************************************************************
  Alessandra Villa                            [email-masked]
  PhD-Student 
  Dipartimento di Chimica Fisica ed Elettrochimica
  Universtita' degli Studi di Milano
  via Golgi 19
  20133 Milano-Italy
*******************************************************************************

---

From: Qiang Cui <[email-masked]>
Date: Thu, 21 Jan 1999 13:43:47 -0500 (EST)

> I summary the answers (4) , maybe it could be halpfull some someone else.

	Sorry for jumping in at such a late stage, but I would recommand
an excellent review on NMR chemical shift as well as spin-spin coupling
calculations: Chem. Rev. 99, 293-352 (1999). Just from the length, you may
imagine that the paper should cover extensive areas. Just one quote from
the review (for fun:-) "We believe that none of the published reviews are
similar in approach and scope to ours: most concentrate on the results;
those that discuss the theory, do not have the character of a general
review"

	Have fun!

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