This is the numerical model for 3-site linear exchange using 3D magnetisation vectors. The assumption that kAC = kCA = 0 has been made to linearise this model. It is selected by setting the model to `NS R1rho 3-site linear'. The constraints pA > pB and pA > pC is used to decrease the size of the optimisation space, as both sides of the limit are mirror image spaces. To simplify the optimisation space for the model as in the `NS R1ρ 3-site' model, the assumptions R2A0 = R2B0 = R2C0 = R20 and R1A = R1B = R1C = R1 have been made.
The equations are the same as for the `NS R1rho 3-site' model except for the relaxation evolution matrix which simplifies to
where δA, B, C are defined as in Equations 11.78a and 11.78b. For the model, the assumptions R1ρA' = R1ρB' = R1ρC' = R1ρ' and R1A = R1B = R1C = R1 have been made.
More information about the NS R1rho 3-site linear model is available from:
The relax user manual (PDF), created 2019-03-08.