B14
The Baldwin 2014 2-site exact solution relaxation dispersion model for SQ CPMG-type data. This model is labelled as B14 in relax.
This model is not implemented yet
Equation
Please see the relax summary of the model parameters here.
These definitions comes from the papers "Supplementary Section 4. Relation to Carver Richards equation".
[math] \tau_{\textrm{CP}} = \frac{1}{4\nu_\textrm{CPMG}} \\ \alpha_- = \Delta R_2 + k_{\textrm{AB}} - k_{\textrm{BA}} \\ \zeta = 2 \Delta \omega \, \alpha_- = h_1\\ \Psi = \alpha_-^2 + 4 k_{\textrm{AB}} k_{\textrm{BA}} - \Delta \omega^2 = h_2\\ \xi = \frac{2\tau_{\textrm{CP}}}{\sqrt{2}}\sqrt{\Psi + \sqrt{\Psi^2 + z^2}} = 2h_3 \tau_{\textrm{CP}} = \tau_{\textrm{CP}}E_0\\ \eta = \frac{2\tau_{\textrm{CP}}}{\sqrt{2}}\sqrt{-\Psi + \sqrt{\Psi^2 + z^2}} = 2h_4 \tau_{\textrm{CP}} = \tau_{\textrm{CP}}E_2\\ D_+=\frac{1}{2}\left(1+\frac{\Psi+2\Delta \omega^2}{\sqrt{\Psi^2+z^2}} \right) = F_0 \\ D_-=\frac{1}{2}\left(-1+\frac{\Psi+2\Delta \omega^2}{\sqrt{\Psi^2+z^2}} \right) = F_2 [/math]
sd [math]a s [/math]
Parameters
The B14 model has the parameters
Reference
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. (10.1016/j.jmr.2014.02.023).
Related models
The B14 model is a linear correction to the CR72 model, and algorithms based on this have significant advantages in both precision and speed over existing formulaic approaches.
Links
The implementation of the CR72 model in relax can be seen in the:
