Key Role of Frustration in Suppression of Magnetization Blocking in Single-Molecule Magnets

State-of-the-art ab initio calculations of a series of endohedral fullerenes Dy n Sc 3– n N@C 80 ( n = 1,2,3) are performed, and their anisotropic magnetic properties are described from the first principles. Contrary to general expectation that molecules of higher nuclearity ( n ) exhibit better magnetic blocking properties, we predict Dy 3 N@C 80 to be a relatively weak single-molecule magnet due to its frustrated ground state. This finding, relevant to polynuclear magnetic molecules in general, demonstrates the crucial role played by magnetic frustration in the suppression of magnetization blocking in single-molecule magnets.