Chemical Shift List

While linking some peaks to my sequence I got this error and since then I am not able either to continue with the assignment to this area nor to navigate to peaks along the chain.
Any idea what should I change?



that’s not looking too good. Could you send us the project (no need for the spectra) at and hopefully we can work out what has gone on and fix it for you.


I have already attached the project, hope it helps!
Thank you

Hi Andromachi,

it turns out you had duplicated Chemical Shifts (ones which were both linked to the some NmrAtom. We’re not quite sure how this can have happened. It would be great if you can remember any (slightly unusual) operations you had been doing before your project got corrupted, so we can identify the bug that allowed this to happen and can make sure projects don’t get into this state again. Things like Undos, deassigning, or moving spectra between Chemical Shift Lists would be possible candidates.
Anyway, I’ve sent you a fixed project and we’ll be putting something on the update server which makes sure that when you open a project it removes any duplicated chemical shifts (there will be a warning that it did this in the terminal window).


Dear Vicky,
Thank you for the fixed project!
When the problem occurred I was mainly checking the connections of the assigned peaks and I was making some changes (deassigning and reassigning some Ca and Cbs using AI and deleting the carbons from nmr chains thinking that like this I would have removed the old shifts)

Similar in another project of mine when I start peaking I get double chemical shifts for the N-H and during the assignment I get more peak counts and duplicate shifts for most of them which then messes up with my connectivities and the assignment inspector. In order to short it out I start deassigning and removing peaks and assigning again ( using undo and deleting from nmr chains).
I think it was also the case for some of my peaks for the project you have corrected.
How could I avoid this so tat I won’t have the same problem with my next projects or if I do how can I fix it afterwards?
Thank you!