Difference between revisions of "Ippcs.m"
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| − | + | {{DISPLAYTITLE:ippcs.m}} __NOTOC__ | |
| − | + | Point electron PCS model fitting. This function fits the point electron model PCS to the experimental pseudocontact shift coordinates and values. It returns the point electron coordinate, the predicted susceptibility tensor, along with the standard deviations for both. | |
| − | + | ==Syntax== | |
| − | + | [mxyz,chi,pred_pcs,s_mxyz,s_chi]=ippcs(nxyz,mguess,expt_pcs) | |
| + | ==Parameters== | ||
nxyz - nuclear coordinates as [x y z] with multiple rows, | nxyz - nuclear coordinates as [x y z] with multiple rows, | ||
| − | at which PCS is | + | at which PCS is to be evaluated, in Angstroms. If |
| − | + | a cell array of such specifications is supplied, | |
| + | the average PCS over them is being used. | ||
| + | |||
mguess - initial guess for the unpaired electron coordina- | mguess - initial guess for the unpaired electron coordina- | ||
tes as [x y z], in Angstroms. | tes as [x y z], in Angstroms. | ||
| − | + | ||
expt_pcs - pseudocontact shift in ppm at each nucleus. | expt_pcs - pseudocontact shift in ppm at each nucleus. | ||
| − | + | ==Returns== | |
| − | + | mxyz - optimized paramagnetic centre coordinates as [x y z], | |
| − | |||
in Angstroms. | in Angstroms. | ||
| − | + | ||
chi - optimized magnetic susceptibility tensor in cubic | chi - optimized magnetic susceptibility tensor in cubic | ||
Angstroms. | Angstroms. | ||
| − | + | ||
pred_pcs - predicted pseudocontact shift at each nucleus with | pred_pcs - predicted pseudocontact shift at each nucleus with | ||
the optimized mxyz and chi, ppm. | the optimized mxyz and chi, ppm. | ||
| + | |||
| + | s_mxyz - standard deviations of paramagnetic centre | ||
| + | coordinates as [x y z], in Angstroms. | ||
| + | |||
| + | s_chi - standard deviations of magnetic susceptibility | ||
| + | tensor elements in cubic Angstroms. | ||
| + | |||
| + | ==Examples== | ||
| + | Multiple examples of point model fits are provided in /nmr_paramag/calbindin and /nmr_paramag/carb_anh directories of the example set supplied with ''Spinach''. | ||
| + | |||
| + | ==Notes== | ||
| + | A good initial guess for the electron location is essential for a successful fit. Point model fails for nuclei positioned closer than about 10 Angstroms to the paramagnetic centre. | ||
| + | |||
| + | ==See also== | ||
| + | [[ppcs.m]], [[lpcs.m]], [[ilpcs.m]], [[ipcs.m]], [[kpcs.m]], [[centroid.m]], [[csa2racs.m]], [[eqmag.m]], [[fieldscan_enlev.m]], [[fieldscan_magn.m]], [[geffect.m]], [[hfc2pcs.m]], [[hfc2pms.m]], [[pcs2chi.m]], [[pcs_combi_fit.m]], [[pms2chi.m]], [[probmax.m]], [[Built-in_experiments]], [[Hyperfine_shift_module]] | ||
| − | + | ''Version 1.9, authors: [[Ilya Kuprov]], [[Elizaveta Suturina]]'' | |
| − | |||
Latest revision as of 19:38, 6 June 2026
Point electron PCS model fitting. This function fits the point electron model PCS to the experimental pseudocontact shift coordinates and values. It returns the point electron coordinate, the predicted susceptibility tensor, along with the standard deviations for both.
Syntax
[mxyz,chi,pred_pcs,s_mxyz,s_chi]=ippcs(nxyz,mguess,expt_pcs)
Parameters
nxyz - nuclear coordinates as [x y z] with multiple rows,
at which PCS is to be evaluated, in Angstroms. If
a cell array of such specifications is supplied,
the average PCS over them is being used.
mguess - initial guess for the unpaired electron coordina-
tes as [x y z], in Angstroms.
expt_pcs - pseudocontact shift in ppm at each nucleus.
Returns
mxyz - optimized paramagnetic centre coordinates as [x y z],
in Angstroms.
chi - optimized magnetic susceptibility tensor in cubic
Angstroms.
pred_pcs - predicted pseudocontact shift at each nucleus with
the optimized mxyz and chi, ppm.
s_mxyz - standard deviations of paramagnetic centre
coordinates as [x y z], in Angstroms.
s_chi - standard deviations of magnetic susceptibility
tensor elements in cubic Angstroms.
Examples
Multiple examples of point model fits are provided in /nmr_paramag/calbindin and /nmr_paramag/carb_anh directories of the example set supplied with Spinach.
Notes
A good initial guess for the electron location is essential for a successful fit. Point model fails for nuclei positioned closer than about 10 Angstroms to the paramagnetic centre.
See also
ppcs.m, lpcs.m, ilpcs.m, ipcs.m, kpcs.m, centroid.m, csa2racs.m, eqmag.m, fieldscan_enlev.m, fieldscan_magn.m, geffect.m, hfc2pcs.m, hfc2pms.m, pcs2chi.m, pcs_combi_fit.m, pms2chi.m, probmax.m, Built-in_experiments, Hyperfine_shift_module
Version 1.9, authors: Ilya Kuprov, Elizaveta Suturina
