This is the analytic CR72 model for 2-site exchange on most times scales (Section 11.3.4 on page ) extended for multiple types of multiple quantum data (MMQ) by Korzhnev et al. (2004a). It is selected by setting the model to `MMQ CR72'. The simple constraint pA > pB is used to halve the optimisation space, as both sides of the limit are mirror image spaces. The equation for the exchange process is
R2eff = ℜ(λ1) - ln(Q), | (11.44) |
where
λ1 | = R2, MQ0 + - νCPMGcosh-1D+cosh(η+) - D-cos(η-), | (11.45) |
D± | = ±1 + , | (11.46) |
η± | = 2±Ψ + , | (11.47) |
Ψ | = ıΔωH + pAkex - pBkex - Δω2 +4pApBkex2, | (11.48) |
ζ | = - 2ΔωıΔωH + pAkex - pBkex, | (11.49) |
and where
Q = ℜ1 - mD+2 + mD+mZ+ - mZ+2 + , | (11.50) |
and
mD± | = ±z± +2Δω, | (11.51) |
mZ | = ±d± -2Δω, | (11.52) |
and
d± | = ΔωH + Δω±ıkex, | (11.53) |
z± | = ΔωH - Δω±ıkex. | (11.54) |
The symbol δ is half of τCPMG or
δ = . | (11.55) |
The references for this model are:
More information about the MMQ CR72 model is available from:
The relax user manual (PDF), created 2020-08-26.