Squeezing of Nitrogen Atomic Orbitals in a Chemical Trap

Fullerenes can act as inert cages for highly reactive nitrogen atoms even at room temperature. Confinement in a cage of less than spherical symmetry as realized in ${\mathrm{C}}_{70}$ leads to a characteristic deformation of the atomic charge and spin distributions which can be sensed by magnetic resonance techniques. A quantitative analysis of the amount of orbital squeezing is possible by comparison with data of free nitrogen ions.