  Molecular nanomagnets are zero-dimensional spin systems, that exhibit quantum
mechanical behavior at low temperatures. Exploiting quantum-information
theoretic measures, we quantify here the size of linear superpositions that can
be generated within the ground multiplet of high- and low-spin nanomagnets.
Amongst the former class of systems, we mainly focus on Mn12 and Fe8. General
criteria for further increasing such sizes are also outlined, and illustrated
in the case of spin rings. The actual character (micro or macroscopic) of
linear superpositions in low-spin systems is inherently ill-defined. Here, this
issue is addressed with specific reference to the Cr7Ni and V15 molecules,
characterized by an S=1/2 ground state. In both cases, the measures we obtain
are larger than those of a single s=1/2 spin, but not proportionate to the
number and value of the constituent spins.
