Spectrum simulation from shifts and couplings (NS)
This subroutine calculates a spectrum, including second-order effects, from the user’s input values of chemical shifts and coupling constants.
(Note that this is not included in NUTS Lite.)
On entering the NS routine, the calculated spectrum (which does not yet exist) is shown in red.
To display the real spectrum (in blue) also, select Both Spectrum and Calculation from the Display menu, or type B.
The cursor can be used to display chemical shifts and couplings, just as in the base level of NUTS.
Typing A, or selecting Add/Edit Simulation Data from the Edit menu, brings up a dialog box allowing entry of chemical shifts and other parameters.
First, enter the number of nuclei in the spin system in the upper left corner.
You can go back and forth between this box and the spectrum by clicking on Accept Changes or Accept and Recalculate. Using Accept Changes does not calculate the spectrum, so is the quickest way to enter an initial set of values. Use Accept and Recalculate when you want to see the effect of newly entered values. To enter coupling constants, click on the button in the lower right corner.
Fill in coupling constants, then click OK to return to display of the calculated spectrum or "Accept and Return to Chemical Shifts" to return to the previous parameter input box.
The calculated spectrum is shown in red.
The scale of the calculated spectrum can be adjusted without recalculating by typing L or selecting Change LB/Amplitude from the Edit menu.
The normal scaling tools, such as the scroll bar, affect both spectra.
Zoom can be used to view details. Enter the Zoom routine by typing Z (not ZO) or from the Display menu.
Select the region to expand as usual by holding down the left mouse button and dragging……
and type Ctrl-E to display the expanded region.
Values of shifts and couplings can be adjusted to optimize the match.
A Simplex fit can be performed, but due to the huge number of calculations involved, it is best to get close manually before attempting a fit.
Other options include displaying the difference between calculated and actual spectrum and saving the calculated spectrum as an FID.
Last updated: 12/31/97.