Figure 2: Molecular structure and internal dynamics in M₂@C₈₀(CH₂Ph).

(a) Molecular structure of Dy₂-I from single-crystal X-ray diffraction shown with 50% thermal ellipsoids. Only the major positions of Dy atoms (occupancy near 70%) are shown, the belt of hexagons around which metal dimer can rotate is highlighted yellow. (b) Same as a but showing the molecule in a different orientation and with all Dy positions (green). (c) Molecular dynamics trajectory of Y₂@C₈₀(CH₃) propagated for 60 ps at 300 K, Y atoms are shown green, displacements of carbon atoms are not shown for clarity. (d) Probability density to find metal atoms derived from molecular dynamics simulations and plotted with two isosurfaces (solid, isovalue 0.25, high probability; transparent, isovalue 0.025, lower probability; C_s symmetry of the C₈₀(CH₂Ph) moiety was taken into account in calculations of probability distribution). In b–d, the molecules are oriented so that the addend is located on the opposite side of the molecule.