Chemex fits look weird

[sucha1512]

Hi I am trying to analyse my trosy cpmg, and the fits look weird. can you let me know the problem? I have calculated errors from s to n ratio
experiments.pdf
Can you let me know what to do?

[viochemist]

Hello, The pdf you show does not appear to have much (quantifiable) exchange, although the R2's are very high so this must have been a real effort to get! These types of fits typically result from poor initialization of parameters. I find starting with simple models on an individual basis helps to find good starting points and locate those residues with the most likelihood of success. Then, when doing a global fitting, use the updated values (R2, DeltaOmega, pb, kex) that you estimate from the initial fits and use only those residues where the exchange appears significant. If you are able to nail down reliable kex and pb values, then create a method with those as fixed values and attempt to fit the rest of the residues. Just my 2¢ Alex *Dr Alexandar L Hansen <https://osu.academia.edu/AlexandarHansen>* Lead Research Scientist CCIC & Gateway NMR Facility R224 CBEC, 151 W Woodruff Ave, Columbus, OH 43210 614.292.7133 Office / 716.341.8476 Mobile ***@***.*** ccic.ohio-state.edu

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On Wed, Oct 2, 2024 at 10:11 AM sucha1512 ***@***.***> wrote: Hi I am trying to analyse my trosy cpmg, and the fits look weird. can you let me know the problem? I have calculated errors from s to n ratio experiments.pdf <https://github.com/user-attachments/files/17230638/experiments.pdf> Can you let me know what to do? — Reply to this email directly, view it on GitHub <#283>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AA5H4JKG3SQSGSP5P56KTX3ZZP5K5AVCNFSM6AAAAABPHYSLJ6VHI2DSMVQWIX3LMV43ASLTON2WKOZSGU3DCOBQGE2TKNI> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>