Ippcs.m

Fits the point electron model PCS to the experimental pseudocon- tact shift coordinates and values. Syntax:

      [exyz,chi,pred_pcs]=ippcs(nxyz,mguess,expt_pcs)

Parameters:

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

    mguess   - initial guess for the unpaired electron coordina-
               tes as [x y z], in Angstroms.

    expt_pcs - pseudocontact shift in ppm at each nucleus.

Outputs:

    exyz     - optimized unpaired electron 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.

Note: a good initial guess for the electron location is essential for a successful fit.