Tim also sends the following:
This error message is a legitimate one to make sure that you don't get
multiple resonance records for exactly the same thing. It occurs when you
try to assign atoms to something that is already assigned elsewhere
(beyond the assignment tolerance). It is not something you want to simply
bypass.
If the resonance has accidentally been placed elsewhere, as David
suggested, you can see where by looking at the resonance info, e.g. via
the Atom Browser click the atom and [Show Resonances] then in the
resonance table [Info]. Any single bogus assignment can be removed from
the peak before deleting the resonance (or editing its shift which is
allowed if not assigned to peaks).
If there is a genuinely large uncertainly in the precision of shifts (i.e.
broad linewidths) then the assignment tolerance (set at
Experiment:Speactra - Tolerances) could be made wider. Also the "Double
Tolerances" option in the Assignment Panel may help. The point here is
that the assignment is made to the existing resonance/atoms, even if they
are separated a bit from the peak position; no new/duplicate resonance is
assigned.
If the shift differences are not minor and the peaks are in genuinely
different positions, such that you wouldn't want to average their
locations to get the underlying shift, then the solution is to use a
separate shift list for the experiment that has moved. The one assignment
can then have two different shifts, depending on experimental conditions.
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