On Wed, 11 Dec 2002 owner-adf-list_at_scm.com wrote:
> A friend of mine is studying (from the experimental side) the shift in
> the isotropic shieldings that occurs in some organic species when some
> hydrogens are replaced by deuterium atoms.
> I know that ADF allows to change the atomic mass of a given element at
> the "create" level, so I can define a deuterium atom with no problems.
> But, can I expect some appreciable changes in the isotropic shieldings
> obtained through an NMR job using that approach to simulate isotopic
> effects?
> Thanks in advance.
> Regards,
>
> Reinaldo

Reinaldo,

The short answer is "no". A good explanation as to why this is the case,
see:

K. Ruud, P.-O. Astrand, and P.R. Taylor "Zero-point Vibrational Effects
on Proton Shieldings: Functional-Group Contributions from ab Initio
Calculations", J.Am.Chem.Soc. 2001, 123, 4826-4833

Serguei

---
Dr. Serguei Patchkovskii
Tel: +1-(613)-991-2719
Fax: +1-(613)-947-2838
E-mail: Serguei.Patchkovskii_at_nrc.ca
Coordinator of Modelling Software
Theory and Computation Group
Steacie Institute for Molecular Sciences
National Research Council Canada
Room 2006/8, 100 Sussex Drive
Ottawa, Ontario
K1A 0R6 Canada