Author: tlinnet
Date: Fri May 2 11:57:07 2014
New Revision: 22918
URL: http://svn.gna.org/viewcvs/relax?rev=22918&view=rev
Log:
Python API documentation corrections for the model B14.
sr #3154: (https://gna.org/support/?3154) Implementation of Baldwin (2014)
B14 model - 2-site exact solution model for all time scales.
"This follows the tutorial for adding relaxation dispersion models at:
http://wiki.nmr-relax.com/Tutorial_for_adding_relaxation_dispersion_models_to_relax#Adding_the_model_to_the_list";
The B14 model is explained in: http://wiki.nmr-relax.com/B14.
Modified:
trunk/lib/dispersion/b14.py
Modified: trunk/lib/dispersion/b14.py
URL:
http://svn.gna.org/viewcvs/relax/trunk/lib/dispersion/b14.py?rev=22918&r1=22917&r2=22918&view=diff
==============================================================================
--- trunk/lib/dispersion/b14.py (original)
+++ trunk/lib/dispersion/b14.py Fri May 2 11:57:07 2014
@@ -41,6 +41,7 @@
=========
The equation used is::
+
R2A0 + R2B0 + kex Ncyc 1 ( 1+y
1-y )
R2eff = ------------------ - ------ * cosh^-1 * v1c - ------ ln( ---
+ ------------------ * (v2 + 2*kAB*pD ) )
2 Trel Trel ( 2
2*sqrt(v1c^2 -1 ) )
@@ -50,6 +51,7 @@
Trel ( 2 2*sqrt(v1c^2 -1 )
)
Which have these following definitions::
+
v1c = F0 * cosh(tauCP * E0)- F2 * cosh(tauCP * E2)
v1s = F0 * sinh(tauCP * E0)- F2 * sinh(tauCP * E2)
v2*N = v1s * (OB-OA) + 4OB * F1^a * sinh(tauCP * E1)
@@ -57,23 +59,20 @@
v3 = ( v2^2 + 4 * kBA * kAB * pD^2 )^1/2
y = ( (v1c-v3)/(v1c+v3) )^NCYC
-Note, E2 is complex. If |x| denotes the complex modulus:<br>
+Note, E2 is complex. If |x| denotes the complex modulus::
+
cosh(tauCP * E2) = cos(tauCP * |E2|)
sinh(tauCP * E2) = i sin(tauCP * |E2|)
The term pD is based on product of the off diagonal elements in the CPMG
propagator (Supplementary Section 3).
-It is interesting to consider the region of validity of the Carver
Richards result.
-The two results are equal when the correction is zero, which is true when
+It is interesting to consider the region of validity of the Carver
Richards result. The two results are equal when the correction is zero,
which is true when::
sqrt(v1c^2-1) ~ v2 + 2*kAB * pD
-This occurs when 2*kAB * pD tends to zero, and so v2=v3.
-Setting "kAB * pD" to zero, amounts to neglecting magnetisation that
starts on the ground state ensemble and end on the excited state ensemble
and vice versa.
-This will be a good approximation when pA >> p_B.
+This occurs when 2*kAB * pD tends to zero, and so v2=v3. Setting "kAB *
pD" to zero, amounts to neglecting magnetisation that starts on the ground
state ensemble and end on the excited state ensemble and vice versa. This
will be a good approximation when pA >> p_B.
-In practise, significant deviations from the Carver Richards equation can
be incurred if pB > 1 %.
-Incorporation of the correction term into equation (50), results in an
improved description of the CPMG experiment over the Carver Richards
equation.
+In practise, significant deviations from the Carver Richards equation can
be incurred if pB > 1 %. Incorporation of the correction term into
equation (50), results in an improved description of the CPMG experiment
over the Carver Richards equation.
kex is the chemical exchange rate constant, pA and pB are the populations
of states A and B, and delta_omega is the chemical shift difference between
the two states in ppm.
_______________________________________________
relax (http://www.nmr-relax.com)
This is the relax-commits mailing list
relax-commits@xxxxxxx
To unsubscribe from this list, get a password
reminder, or change your subscription options,
visit the list information page at
https://mail.gna.org/listinfo/relax-commits
Re: r22918 - /trunk/lib/dispersion/b14.py