Get more assignment possibilities

The assignment of a peak usually is done via the Assignment: Assignment Panel popup where the assignment possibilities for each peak dimension are shown in the columns on the right hand side:

The assignment possibilities only show resonances that are within the chemical shift tolerances. So it is possible to change the number of assignment possibilities by setting the chemical shift tolerances. The chemical shift tolerances can be set on a per dimension and a per spectrum basis in M: Experiment: Spectra, {Tolerances}:

The |Assignment Tolerance| column defines the chemical shift tolerance (typically in ppm) that is applied for assignment of peak dimensions to resonances; Assignment possibilities are only included if the resonance’ chemical shift is within the peak location +- the tolerance. Resonances with shifts outside this region are not considered as assignment possibilities. Simply click on the table cell to edit the tolerances.

A fast way to allow a higher tolerance without changing the spectrum tolerances is to use the “Double Tolerances” in the Assignment: Assignment Panel popup, which doubles the assignment tolerance for each dimension and typically increases the number of assignment possibilities.