The NS 2-site R

This is the numerical model for 2-site exchange using 3D magnetisation vectors.
It is selected by setting the model to `NS R1rho 2-site'.
The simple constraint
*p*_{A} > *p*_{B} is used to halve the optimisation space, as both sides of the limit are mirror image spaces.

For this model, the equations from Korzhnev et al. (2005b) have been used.
The
R_{1ρ} value for state A magnetisation is defined as

R_{1ρ} = - ⋅lnM_{0}^{T}⋅e^{R⋅Trelax}⋅M_{0}, |
(11.81) |

where

M_{0} |
= , | (11.82) |

θ |
= arctan. | (11.83) |

The relaxation evolution matrix is defined as

R = , |
(11.84) |

where
*δ*_{A, B} is defined in Equations 11.78a and 11.78b.

More information about the NS R1rho 2-site model is available from:

- the relax wiki at http://wiki.nmr-relax.com/NS_R1rho_2-site,
- the API documentation at http://www.nmr-relax.com/api/3.2/lib.dispersion.ns_r1rho_2site-module.html,
- the relaxation dispersion page of the relax website at http://www.nmr-relax.com/analyses/relaxation_dispersion.html#NS_R1rho_2-site.

The relax user manual (PDF), created 2019-03-08.