chem_mjf
第2楼2006/08/20
IMPROVED CONVERSION OF BRUKER DATA
In Varian NMR News 1997-04-08 we gave you a recipe for converting data from
Bruker "D" series (AVANCE, DPX, DRX, DMX) spectrometers. That recipe involved
left-shifting the FID by a number of points that is calculated by a macro
"maclib/lsbru" from the Varian NMR User Library.
We have just posted an enhanced version of this contribution at
http://www.varianinc.com/nmr/apps/usergroup/userlib.html
The new version of "lsbru" offers several enhancements:
- if the parameters "decim" and "dspfvs" (DSP firmware version) are present,
"lsbru" uses an up-to-date formula for calculating the FID left-shift. This
information was originally collected by W.M. Westler (NMRFAM, Madison, WI)
and kindly forwarded to the editor by Juan Carlos Cobas, University of
Santiago de Compostela, Spain.
- different from the original macro, "lsbru" does NOT use "lsfid" any longer
("lsfid>0" discards FID data points), but rather calculates "lp" as
"lsfid*360", then setting "lsfid=0" (as already suggested in Varian NMR
News 1997-04-08). This corresponds to a CIRCULAR left-shift, i.e., it does
not discard data.
- as the resulting "lp" values may be as large as 25000 and more, "lsbru"
also adjusts the parameter limits of "lp" to cover a range of -36000 up to
36000. This way, manual fine-corrections to "lp" are still possible.
Note that such heavy left-shifting is NOT required with digitally filtered
data acquired on Varian spectrometers - our DSP algorithm is time corrected
and does not cause phase distortions.
Varian_NMR_News_2002-03-10
+++++++++++++++++++++++++++++++++++++++++++++++++
Bruker to Varian (Prior to 2002)
Converting Xwinnmr to Vnmr format for ease processing
Here is the method for getting AVANCE data into vnmr !!
1) Data to convert:/u/data/username/nmr/burkerspectrum/1/ser or fid
2) On the SUN or the SGI, cd into the top-level directory for the data you want to convert; suppose the Bruker data set is called "burkerspectrum" and you FTP that into your home directory; then cd ~/brukerspectrum (within VNMR command line, switch to this directory)
3) Within VNMR, you can convert the data as follows
convertbru('1','-omsb')
sread('1.cv','/vnmr/parlib/bruker')
lsbru
wft
You are converting the 1 (numeric one) data set saved under brukerspectrum.
4) You can do the first steps at the Unix prompt:
>cd ~home_directory/garbage
>convertbru 1 /vnmr/parlib/bruker -omsb
Add the -f to the end of the line if you want to write over an existing converted file name.
5) That should do it. With the tocsy dataset we tried this on, however, there was a problem with the F2 axis that could be corrected with reffreq=sfrq and reffrq and reffrq are the parameters that are used to calculate the ppm in vnmr. Factors of 2 confusion in vnmr should be expected here, since it is usually very hard to tell the Bruker size how to take care of factors of two. Easier (hopefully) to fix with reffrq than to describe.
lsbru: a routine that Milo Webster wrote (NMRFAM) and can be found in the /vnmr/userlib (userlib is part of all VNMR releases, so they have it, and just need to expand the routine into the user's maclib if is not already present in the /vnmr/maclib.
6) After converting to VNMR there are several things that must be done:
(a) proc1 should be set to 'ft' or 'lp' (somehow, proc1='rft' as default in the output),
(b) lsfid=70 if the over sampling points is 64.