Quantum Monte Carlo simulations of a giant {NiGd} cage with a S = 91 spin ground state.

The detailed analysis of magnetic interactions in a giant molecule is difficult both because the synthesis of such compounds is challenging and the number of energy levels increases exponentially with the magnitude and number of spins. Here, we isolated a {NiGd} nanocage with a large number of energy levels (≈5 × 10) and used quantum Monte Carlo (QMC) simulations to perform a detailed analysis of magnetic interactions. Based on magnetization measurements above 2 K, the QMC simulations predicted very weak ferromagnetic interactions that would give a record S = 91 spin ground state.

Quantum Monte Carlo Simulations and High-Field Magnetization Studies of Antiferromagnetic Interactions in a Giant Hetero-Spin Ring.

Chromium lanthanide heterometallic wheel complexes {Cr Ln } (Ln=Gd, Dy and Y) with alternating metal centres are presented. Quantum Monte Carlo simulations reveal antiferromagnetic exchange-coupling constants with an average of 2.1 K within the {Cr Gd } wheel, which leads to a large ground spin state (S =16) that is confirmed by magnetization studies up to 20 Tesla.