  A judicious analysis of previously published experimental data leads one to
conclude that the ground state of iron(II) phthalocyanine is an orbitally
degenerate spin triplet $a_{1g}^2 e_g^{\uparrow\downarrow\uparrow}
b_{2g}^{\uparrow}$ ($^3E_g$). The ligand field parameters, in relation to
Racah's $C$, are approximately as follows: $B_{20}/C=0.84$, $B_{40}/C=0.0074$.
The uniqueness of this result is demonstrated by means of a special diagram in
the $B_{20}/C-B_{40}/C$ plane (under additional conditions that
$B_{44}/B_{40}=35/3$ and $B/C=0.227$). The system is in a strong-ligand-field
regime, which enables the use of single-determinant techniques corrected for
correlations within the 3d shell of Fe.
