NUTS Help
Processing Varian HMBC data
Varian acquires HMBC data as hypercomplex, even though the data is not phasesensitive, and a magnitude calculation is done at the end of processing. In a hypercomplex experiment, 2 FIDs are acquired for each t_{1} time point, with a phase shift of one pulse. After FT in the direct dimension, the real halves of each pair of spectra are combined to create complex interferograms in the indirect dimension.
Varian HMBC spectrum of strychnine.
This data set can be downloaded, along with processing macros.
Using Arrayed Mode, processing can be done using a macro (below) or simply by entering the following commands using the command line.
Users with the standard 2D version cannot use Arrayed Mode, and can process with a different macro (below).
See also: macros, 2D processing, displaying 2D data
Arrayed Mode processing from the command line
AR  enter arrayed mode 
IM  import file called fid 
S#  set phase shift for sine multiplication to 45 
MS MS  apply cosine squared window function 
FT  
TR TR ST  “tag” real half of each slice and store 
TD  transpose data 
MS MS  
ZF ZF  zerofill (experience has shown there is benefit from doing several ZFs, even 4 times) 
FT  
MC  magnitude calculation 
BC  remove any DC and tilt in baseline 
TD  to view data with direct dimension horizontal 
MH  set minimum height to 5 (good starting guess for contour threshold) 
SS  set scale 
IP  intensity plot 
Be sure to save the processed data.
NUTSMACRO Varian hmbc data (hypercomplex and magnitude) for NUTSProfessional set array_on ask filea ga set s# 45 ;window fcn is sinesquared bc ms ms ft ; combine slices for hypercomplex data tr tr st ;transpose data td ;2nd dimension processing ;window fcn is sinesquared and we do one zerofill ; magnitude calculation ms ms zf ft mc bc ;transpose data td set mh 5 ss ip end
Note that NUTS remains in Arrayed Mode at the end of the macro. Be sure to save the final data.
Macro without Arrayed Mode
Processing is done one 1 slice at a time, so the sequence of commands is done in a Link, which is repeated for each slice.
Temporary files are written at each stage of processing, so the macro must reset the file names at each stage. Be sure to save the final result.
NUTSMacro Varian HMBC, hypercomplex and magnitude  
ask filea ga  Macro asks for FID to open 
set sl 1 set s# 45  window function used here is sine squared, applied with ms ms after setting s#=45 
set filec ft1.2d  
ga bc ms ms ft bc tr ia ga bc ms ms ft bc tr st in  1st dimension processingGA reads in the first slice BC removes DC offset of the 2 halves of the FID MS MS applies cosine squared BC after FT removes DC and tilt in baseline TR “tags” this to be the real half of the complex FID in t_{1 }IA increments slice counter for File A_{ }GA reads in the next slice, which is processed same way TR “tags” this to be the imaginary half of the complex FID in t_{1} ST saves the 2 halves, and IN increments the file pointers and loops to the beginning of the Link 
set filec td.2d set filea ft1.2d set sl 1 ga td  reset file namestranspose data 
set filea td.2d set filec ft2.2d set sl 1  reset file names 
ga ms ms zf ft mc bc sc in  2nd dimension processing 
set filea ft2.2d set filec final.2d set sl 1 ga td  reset file namestranspose data

set filea final.2d ga ss set mh 5 ip end  open file data setset contour threshold (MH = 5) set scale, display intensity plot 
Last updated: 4/27/01