Kpcs.m

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Computes pseudocontact shifts using the PDE method.

Syntax

    [pcs_vals,pcs_cube]=kpcs(probden,chi,ranges,nxyz,method)

Description

Computes the three-dimensional distribution of pseudocontact shift field by solving Kuprov-Charnock equation for PCS. For further information on the equations and algorithms used in this function see http://dx.doi.org/10.1039/C4CP03106G

Arguments

    probden - paramagnetic centre probability density cube.

    chi     - electron magnetic susceptibility tensor in cubic Angstroms.

    ranges  - Cartesian axis extents for the electron spin density cube
              as [xmin xmax ymin ymax zmin zmax] in angstroms.

    nxyz    - nuclear coordinates as [x y z] with multiple rows) at which
              PCS is to be evaluated, in Angstroms.

    method  - 'fft' for Fourier transfrom solver (recommended), 'fdiff'
              for a finite difference solver.

Returns

    pcs_vals - pseudocontact shift in ppm at each nucleus.

    pcs_cube - pseudocontact shift field on the same grid as the spin 
               density supplied.

Examples

See the pseudocontact shift analysis tutorial and the examples in nmr_paramag directory of the standard example set supplied with Spinach.

Notes

Minimal three-point schemes are used for the finite difference operators. Increase stencil size in the source code if you have enough memory. Beware of the periodic boundary condition effects - leave enough space on all sides of your paramagnetic centre probability density for the wraparound PCS to become negligible.

See also

ppcs.m, ipcs.m, ippcs.m, ilpcs.m, lpcs.m


Version 1.9, authors: Elizaveta Suturina, Gareth Charnock, Ilya Kuprov