Wrong shielding value from NMR calculation

[yimanu]

Thanks V

I am sorry, it was my error. I was comparing two different levels of
theory.
I think I assumed that since the TMS value was close then the monomer
should also be similar.

Lekpa


On Mar 11, 2:10 pm, vweber <valer... at hotmail.com> wrote:
> Hi Lekpa
>
> Running g03 gives me the following shift for your systems
>
> mono_nmr.out:  2  Si   Isotropic =   385.4381   Anisotropy =
> 33.7255
> tms_nmr.out:  1  Si   Isotropic =   349.7620   Anisotropy =     0.0699
>
> and the cp2k (cvs) gives
> mono-nmr-SHIFT-1.data:  ISOTROPY =     384.7861  ANISOTROPY =
> 36.7078
> tms-nmr-SHIFT-1.data:  ISOTROPY =     351.1586  ANISOTROPY =
> 1.5007
>
> I would suggest you to use the GAUGE ATOM in the CURRENT section and
> you would get
>
> mono-nmr-SHIFT-1.data:  ISOTROPY =     385.9543  ANISOTROPY =
> 33.9237
> tms-nmr-SHIFT-1.data:  ISOTROPY =     349.5128  ANISOTROPY =
> 0.1374
>
> which are slightly closer to the g03 runs.
>
> What is the value you get with the other software?
>
> V
>
> On Mar 9, 10:24 am, Lekpa Duukori <duu... at gmail.com> wrote:
>
> > Dear All,
>
> > I am having some problems with nmr calculations using cp2k.
> > I am using a 2009-02-11 compilation.
>
> > I am trying to calculate chemical shifts and I started with the silicate
> > monomer (Si(OH)4).
> > The following shielding values was obtained
>
> > Monomer: ISOTROPY =     385.1320  ANISOTROPY =      35.3885
> > TMS:         ISOTROPY =     350.0942  ANISOTROPY =       0.6521
>
> > The value for TMS is close to what I obtain using other software but for the
> > monomeric specie,
> > its way off.  Does anyone know what might be the cause of this ?
>
> > My input files are attached.
>
> > Thanks.
>
> > Lekpa.
>
> >  files.gz
> > 2KViewDownload