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B14
,The Baldwin 2014 2-site exact solution relaxation dispersion model for [[SQ CPMG-type data]] for all time scales whereby the simplification {{:R2Azero}} = Intro ={{:R2Bzero}} is assumed. This model is labelled as '''B14''' in [[Relaxation dispersion citation for relax|relax]].
The Baldwin 2014 advantage of this code will be that you'll always get the right answer provided you've got 2-site exact solution relaxation dispersion model for [[SQ CPMGexchange, in-phase magnetisation and on-type data]] for all time scales whereby resonance pulses. == Comments from the simplification $R_{2A}^0$ Author == $R_{2B}^0$ is assumedDuring the implementation of model B14, Andrew Baldwin wished to raise the attention to: '''1) Danger of errors of approximations'''. This model is labelled as <br>'''B142) That optimal accuracy analysis should include off resonance effects''' in [[Relaxation dispersion citation for relax. Please read:* {{#lst:Citations|MyintIshima09}}* {{#lst:Citations|relax]].Bain11}}
== Equation ==
<math>
\tau_{\textrm{CP}} = \frac{1}{4\nu_\textrm{CPMG}} \\
\alpha_- = R_2^A - R_2^B + k_{\textrm{AB}} - k_{\textrm{BA}} \\
\zeta = 2 \Delta \omega \, \alpha_- = h_1\\
\Psi = \alpha_-^2 + 4 k_{\textrm{BA}} k_{\textrm{AB}} - \Delta \omega^2 = h_2\\
== Parameters ==
The B14 model has the parameters {$R_{2A{:R2zero}^0$, $R_{2B}^0$, $...$, $p_A${{:pA}}, $\Delta\omega${{:Deltaomega}}, $k_{ex{:kex}}$}.
== Code ==
[https://gna.org/support/?3154 Here is gna.org tracker that followed this code. It includes valuable comments.]
The library code.<br>http://svn.gna.org/viewcvs/*checkout*/ {{relax/trunk/url|path=lib/dispersion/b14.py?revision=HEAD}}
The target function. The func_B14().<br>http://svn.gna.org/viewcvs/*checkout*/ {{relax/trunk/url|path=target_functions/relax_disp.py?revision=HEAD}}
=== Example graph of test data ===
The reference for the B14 model is:
* A.J. Baldwin (2014). An exact solution for R2,eff in CPMG experiments in the case of two site chemical exchange. ''J. Magn. Reson.'', 2014. ([http{{#lst://dx.doi.org/10.1016/j.jmr.2014.02.023 10.1016/j.jmr.2014.02.023]).Citations|Baldwin14}}
== Related models ==
== Links ==
The [[Relaxation dispersion citation for relax|implementation of the CR72 B14 model in relax]] can be seen in the:* [http://www.nmr-relax.com/manual/The_reduced_B14_2_site_CPMG_model.html relax manual],* [http://www.nmr-relax.com/api/3.1/lib.dispersion.b14-module.html API documentation],* [http://www.nmr-relax.com/analyses/relaxation_dispersion.html#B14 relaxation dispersion page of the relax website].
== See also ==
[[Category:Models]][[Category:Dispersion models]][[Category:Relaxation_dispersionanalysis]]