Dimer-dimer Correlations and Magnetothermodynamics of S=1/2 Spherical Kagome Clusters in W72V30 and Mo72V30

Numerical diagonalization methods are employed to study spin-1/2 spherical kagome clusters realized in W72V30 and Mo72V30, where the former is expected to have the ideal symmetry Ih and the latter is a little distorted. For the ideal model with Ih symmetry we calculate spin correlation functions in the ground state, which resemble the spin-1/2 kagome antiferomagnet closely. We also present the integrated density of states for W72V30 and Mo72V30, and discuss the difference in magnetothermodynamics for both materials.