Hi there
I am having trouble locating and adjusting noesy-chsqc peaks without volume. When setting up the Xplor calculation I had 96 cnoesy peaks without volumes. After using the estimate peak volumes and estimate current peak volume shortcuts, I still have 14 peaks without volumes.
I am curious if there is a way to identify where and what peaks remain without volume. I have attached a screen shot below.
Thank you kindly
Hi,
AnalysisAssign/Structure can be a bit fussy about generating volumes for peaks if they don’t fit well enough to the default/selected peak shape.
You can find peaks with zero volume by opening your peak list (expand the spectrum in the left hand browser pane → right click on a peak list → Open as module) and sorting on the Volume column by clicking on the column header.
One approach would be to set all your peak volumes to peak heights as per Vicky’s earlier post.
Hi,
The problem is that volumes are always calculated from a fitting. So if you place your peaks manually, rather than managing to fit them, then you are not going to be able to get a volume value.
So don’t forget to use the RG (refit peak group) command as well a the RP (refit single peak) command to help you fit your peaks nicely. Sometimes it can be really hard to fit the peaks well, especially if you have shoulders etc. The limited number of points we use for the fitting also means that you may get different results depending on your starting point. If there is a shoulder you don’t want to include or something like that, then you can always pick several peaks and fit them together, but then delete the ones you don’t want to keep.
Vicky
