CCL: NMR chemical shifts - STOs v. GTOs

[Reynier Suardiaz del Río <reynier""fq.uh.cu>]

  For the evaluation of  coupling  constants where the dominant
 term is
 the Fermi Contact would be better to use STO, but they are most time
 consuming and not all the coupling have these dominance (some couplings
 with F or N). The problem is solved using GTO with "tight s functions",
 the s parts of  the basis set completly decontracted.
  The ADF program use STO and have a subprogram that compute coupling
 constants (CPL) i don't know a comparison but i think the difference
 between STO and GTO with  tight s functions is negligible.
 
 
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     ________________________________
 	Reynier Suardiaz del Río
 	Dpto. de Química Física
 	Facultad de Química
 	Universidad de la Habana
 	e-mail: reynier""fq.uh.cu
 	web: http://www.fq.uh.cu
     ________________________________
 
 
 CCL wrote:
> Sent to CCL by: "Shobe, David" [dshobe---sud-chemieinc.com]
>  --Replace strange characters with the "at" sign to recover email address--.
>  I just thought of something.  I've never heard this (I never do NMR
>  calculations), but would a program that uses Slater-type orbitals have a huge
>  accuracy advantage over one that uses Gaussian-type orbitals?  It makes sense
>  because the STO's are more accurate in the near-nucleus area than GTO's.
>  --David Shobe, Ph.D., M.L.S.
>  Süd-Chemie, Inc.
>  phone (502) 634-7409
>  fax (502) 634-7724
>  Don't bother flaming me: I'm behind a firewall.
>  -----Original Message-----
> > From: owner-chemistry""ccl.net [mailto:owner-chemistry""ccl.net]
> >    
> Sent: Thursday, September 29, 2005 1:12 AM
>  To: Shobe, David
>  Subject: CCL: W:Iodo NMR chemical shifts
>  Sent to CCL by: "Gisele deFreitas Gauze" [giselegauze()yahoo.com.br]
>  --Replace strange characters with the "at" sign to recover email address--.
>  I am calculating chemical shifts to alfa iodine ketones, with Gaussian (3-21G
>  and lanl2dz) and the results are very poor. Anyone knows about specific iodine
>  basis set to perform these calculation.
>  Thanks for while
>  Gisele de Freitas Gauze
>  giselegauze""yahoo.com.br
>  Maring-Paran-Brasilhttp://www.ccl.net/cgi-bin/ccl/send_ccl_messageE-mail to
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--
     ________________________________
 	Reynier Suardiaz del Río
 	Dpto. de Química Física
 	Facultad de Química
 	Universidad de la Habana
 	e-mail: reynier""fq.uh.cu
 	web: http://www.fq.uh.cu
     ________________________________