Abstract:
A relativistic study of spectroscopic properties of the endohedral fullerenes Ng@Cq 60 (where Ng
= He, Ne and q = 0, ±1, ±2 are the charges) associated with the C60 molecule has been done using the
equation of motion coupled cluster (EOM-CC) methodology. Specific properties estimated are the
transition energies, dipole oscillator strengths, and transition probabilities for the low-lying excitations
1s2(1S0) → 1snp (1P1) (n = 2, 3, 4) for He@Cq 60 and 1s22s22p6 (1S0) → 1s22s22p5ns/nd (1P1) (n
= 3, 4) for Ne@Cq
60, which have been compared with those for the isolated atom to depict the
confinement effect of the host molecule on the encapsulated atom. This is accomplished by introducing
an effective potential to the atomic Hamiltonian induced by the fullerene moiety and its charge. The
EOM-CC results have been compared with those estimated with the random phase approximation
(and configuration interaction singles) to understand the effect of electron correlation under such
confinement. The systematic and interesting behavior of the properties is highlighted indicating the
effect of fullerene cage potential on the redistribution of electron density of the guest atom.
