Thermodynamics and spin mapping of quantum excitations in a Heisenberg spin heptamer

In this study, we examine the thermodynamics and spin dynamics of spin-1/2 and spin-3/2 heptamers. Through an exact diagonalization of the isotropic Heisenberg Hamiltonian, we find the closed-form, analytical representations for thermodynamic properties, spin excitations, and neutron-scattering structure factors. Furthermore, we investigate the clusterlike excitations of quantum spin heptamer in the three-dimensional pyrochlore lattice material MgCr2O4. Using a spin mapping of the spin-1/2 heptamer excitations, the calculated structure factors of the spin-3/2 heptamer are to be determined, which provides clarification for the spin excitations in MgCr2O4. Overall, this study demonstrates the ability to use the spin mapping of structure factors for small spin systems to analyze more complex structures.