Hi, Can somebody clarify the use of ambiguous assignments for CH2 groups, please. If I create a new resonance in peak assignment popup and use, for example, Hb* to assign it, an additional resonance will be created and one resonance will be assigned to Hb2 and the other to Hb3 proton. After that both resonances appear to be independent. I can add or remove them separately as contributions to peaks, deassign one of them and so on. Is there a connection between them, and if there is, what effect it has. What is the difference of using Hb* as opposite to creating two resonances and assigning one to Hb2 and the other to Hb3. Thanks Igor -- Dr. Igor Barsukov Biological NMR Centre, University of Leicester PO Box 138, University Road, Henry Wellcome Building, Leicester LE1 9HN UK E-mail: [log in to unmask] Tel: +44 (0)116 229 7098 FAX: +44 (0)116 229 7053