Hi, The key here is what is meant by R2. There are many different definitions. In relax, the parameter name R2 is defined as:
- In the standard relaxation equations, spin-spin relaxation component. I.e. the part influenced by the spectral density function J(w). - Again in the standard relaxation equations, R2 is used for R2*, where R2* = R2 + Rex. R2* is also defined differently if you look at the exponential decay curves or if you looking at peak widths (for the later there are additional factors broadening the peaks which add to the R2* equation). - For relaxation dispersion, R2 is currently defined as R1rho', i.e. just the parts influenced by the spectral density function. Here R1rho' is the on-resonance part of R1rho, excluding exchange. R2 = R1rho' + Rex could also be defined, which is probably what you are after. The value of R1rho' + Rex has been named many different things by the field and there seems to be no consensus. I have discussed this with Troels at http://thread.gmane.org/gmane.science.nmr.relax.devel/5119/focus=5207. This is a long thread with many discussions about implementing this as an automatically calculated parameter - which in the end would be a great feature. So which R2 value are you after? Regards, Edward On 26 March 2014 12:58, Justin Lecher <j.lec...@fz-juelich.de> wrote: > On 26/03/14 12:47, Troels Emtekær Linnet wrote: >> Hi Justin. >> >> If one have R1, and R1rho, R2 (R1rho') is fitted in: >> http://wiki.nmr-relax.com/DPL94 >> http://wiki.nmr-relax.com/TAP03 >> http://wiki.nmr-relax.com/TP02 >> http://wiki.nmr-relax.com/NS_R1rho_2-site >> >> R1+(R2) can be made by: >> http://wiki.nmr-relax.com/Tutorial_for_R1/R2_Relaxation_curve-fitting_analysis_on_varian_recorded_as_fid_interleaved >> (A tutorial I made for our students in our lab. We have Varian at our >> place). >> >> Best >> Troels >> > > Hi Troels, > > perfect, thanks! I found the wiki pages, but I wasn't sure which one is > the best to choose. Any general suggestion or does it strictly depend on > the type of model which applies best to my system? > > thanks > Justin > > -- > Justin Lecher > Institute of Complex Systems > ICS-6 Structural Biochemistry > Research Centre Juelich > 52425 Juelich, Germany > phone: +49 2461 61 2117 > > > > _______________________________________________ > relax (http://www.nmr-relax.com) > > This is the relax-users mailing list > relax-users@gna.org > > To unsubscribe from this list, get a password > reminder, or change your subscription options, > visit the list information page at > https://mail.gna.org/listinfo/relax-users > _______________________________________________ relax (http://www.nmr-relax.com) This is the relax-users mailing list relax-users@gna.org To unsubscribe from this list, get a password reminder, or change your subscription options, visit the list information page at https://mail.gna.org/listinfo/relax-users
