Thank you guys very much. The problem is solved. It is simply due to
the different conventions for reporting chemical shift tensors.

Cheers,

Eric

--- In simpson-simmol@yahoogroups.com, Pedro Aguiar
<pedrom.aguiar@...> wrote:
>
> As Andy mentioned this relies on how the priorities of the shielding
> tensor components are defined for different conventions. Klaus has a
> nice breakdown of the differences in the Euler angle definitions for
> various relative rotations of the efg and csa tensors for "all"
> conventions and how they relate to the inputs of SIMPSON and
WSOLIDS(http://anorganik.uni-tuebingen.de/klaus/nmr/index.php?p=conventions/conv\
entions

> ).
>
> Cheers,
>
> Pedro
>
> On Feb 27, 2009, at 6:37 PM, Andrew Lipton wrote:
>
> > Well, now you come to the big division among us. Which conventions
> > to use? How did you enter your CSA parameters?
> >
> >
> > span and skew?
> >
> > delta and eta?
> >
> > anisotropy and eta?
> >
> > you could also try reversing the order of the angles. I have also
> > found that the sign of the CSA could vary between conventions, STARS
> > and SIMPSON for example each use delta but the signs are opposite.
> > Sorry but I'm not sure which parameters DMFIT or WSOLIDS use, but I
> > would guess span and skew.
> >
> > Cheers,
> >
> > Andy
> >
> > __________________________________________________
> > Andrew S. Lipton Ph. D.
> > Biological Sciences Division/Cell Biology & Biochemistry Group
> >
> > FUNDAMENTAL AND COMPUTATIONAL SCIENCES DIRECTORATE
> >
> > Pacific Northwest National Laboratory
> > 902 Battelle Boulevard
> > P.O. Box 999, MSIN K8-98
> > Richland, WA 99352 USA
> > Tel: 509-371-6533
> > Fax: 509-371-6546
> > as.lipton@...
> > www.pnl.gov
> >
> >
> > On Feb 27, 2009, at 7:11 AM, mychemistry2001 wrote:
> >
> >> Hi folks,
> >>
> >> I am trying to simulate a static spectrum which combines the
> >> second-order quadrupolar coupling and chemical shift anisotropy. I
> >> set
> >> the angles for quadrupole to be 0 0 0 and the angles for the shift to
> >> be 70 90 80. However, the simulation gives an unexpected shape which
> >> is different from both the experimental and the DMFIT and the
> >> WSOLIDS.
> >> Can anyone help me on this? Thanks a lot.
> >>
> >> The input file is as follows:
> >>
> >> spinsys {
> >> channels 87Rb
> >> nuclei 87Rb
> >> shift 1 -150p -300p 0.7 70 90 80
> >> quadrupole 1 2 7e6 0.5 0 0 0
> >> }
> >>
> >> par {
> >> spin_rate 0
> >> gamma_angles 1
> >> sw 625000
> >> crystal_file zcw4180
> >> np 8192
> >> start_operator I1x
> >> detect_operator I1c
> >> method direct
> >> proton_frequency 600e6
> >> verbose 1101
> >> }
> >>
> >> proc pulseq {} {
> >> global par
> >> set dw [expr 1e6/$par(sw)]
> >> acq x
> >> for {set i 1} {$i < $par(np)} {incr i} {
> >> delay $dw
> >> acq x
> >> }
> >>
> >> }
> >>
> >> proc main {} {
> >> global par tsw
> >>
> >> set f [fsimpson]
> >> fsave $f $par(name).fid
> >> fzerofill $f 65536
> >> faddlb $f 120 0
> >> fft $f
> >> fsave $f $par(name).spe
> >> funload $f
> >> }
> >>
> >>
> >
> >
> >
>