Pms2chi.m

Uses linear least squares procedure on top of Equation 10 from http://dx.doi.org/10.1039/c4cp03106g to extract the susceptibi- lity tensor from DFT hyperfine coupling tensors and experiment- ally observed paramagnetic (contact + pseudocontact) shifts.

             chi=pms2chi(hfcs,shifts,isotopes)

where hfcs is a cell array of 3x3 hyperfine coupling tensors in MHz, shifts is a vector of the observed paramagnetic shifts, ex- cluding the diamagnetic contribution, and isotopes is a cell ar- ray of character strings specifying isotopes that exhibit each of the chemical shifts supplied, for example {'1H','13C'}.