# Magnetic susceptibility trend

So I was recently looking at this website.

http://www.fizika.si/magnetism/MagSusceptibilities.pdf

It lists the susceptibility values for inorganic compounds, and I've noticed that the trends don't appear to follow logic. The stronger the ligand OH, CN etc.., the larger the energy needed to reach the higher orbitals, and thus more paired electrons so a stronger diamagnetic effect, whilst the weaker ligands cause the pairing energy to be higher relative to the energy needed to go up to the higher shells, so less paired electrons so higher magnitude of magnetic susceptibility.

If one takes a look at CuI, CuBr, CuCl, and CuCN we can see that the negative susceptibility values become more positive (from -63, to -49, to -40, to -24) as ligand strength increases. Similarly, some compounds don't follow the trends of stronger ligands like $\ce{NiI2}$, to, $\ce{NiBr2}$, to $\ce{NiCl2}$. How can this be?

Also, I've tried plotting transition metal radius alongside their susceptibility values for bonding w/ Br for same oxidation states. I got a proportional relationship. Apparently, the atomic radius of the transition metal increases the susceptibility. Does this make a bit of sense? I mean, logically, larger radius essentially means larger diamagnetic and hence lower paramagnetic susceptibility values, right?