Module m61b
source code
The Meiboom (1961) 2-site on-resonance skewed population R1rho M61 skew
model.
Description
This module is for the function, gradient and Hessian of the M61 skew
model.
References
The model is named after the reference:
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Meiboom S. (1961). Nuclear magnetic resonance study of the proton
transfer in water. J. Chem. Phys., 34, 375-388. (DOI:
10.1063/1.1700960).
Equations
The equation used is:
pA^2.pB.delta_omega^2.kex
R1rho = R1rho' + -------------------------------------- ,
kex^2 + pA^2.delta_omega^2 + omega_1^2
where R1rho' is the R1rho value in the absence of exchange, kex is
the chemical exchange rate constant, pA and pB are the populations of
states A and B, delta_omega is the chemical shift difference between
the two states, and omega_1 = omega_e is the effective field in the
rotating frame.
Links
More information on the M61 skew model can be found in the:
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r1rho_M61b(r1rho_prime=None,
pA=None,
dw=None,
kex=None,
spin_lock_fields2=None,
back_calc=None,
num_points=None)
Calculate the R1rho values for the M61 skew model. |
source code
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__package__ = ' lib.dispersion '
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Imports:
abs,
array,
isfinite,
min,
sum
r1rho_M61b(r1rho_prime=None,
pA=None,
dw=None,
kex=None,
spin_lock_fields2=None,
back_calc=None,
num_points=None)
| source code
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Calculate the R1rho values for the M61 skew model.
See the module docstring for details.
- Parameters:
r1rho_prime (float) - The R1rho_prime parameter value (R1rho with no exchange).
pA (float) - The population of state A.
dw (float) - The chemical exchange difference between states A and B in rad/s.
kex (float) - The kex parameter value (the exchange rate in rad/s).
spin_lock_fields2 (numpy rank-1 float array) - The R1rho spin-lock field strengths squared (in rad^2.s^-2).
back_calc (numpy rank-1 float array) - The array for holding the back calculated R1rho values. Each
element corresponds to the combination of spin lock field.
num_points (int) - The number of points on the dispersion curve, equal to the length
of the spin_lock_fields and back_calc arguments.
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