Spectroscopy of He atom encapsulated in C60 cage: low lying magnetic dipolar (M1) and magnetic quadrupolar (M2) transitions

The spectroscopic properties of magnetic dipolar and quadrupolar transitions (M1 and M2) of He atom encapsulated under neutral and charged C 60 fullerene cage have been estimated here to understand the effect of cage confinement on the ground state energy ( E), ionization potential (IP), excitation energies (Δ E), and transition probabilities (TPs) of the low lying transitions 1s 2 : 1 S e → 1s ns: 3 S[Formula: see text] and 1s 2 : 1 S e → 1s np: 3 P[Formula: see text] ( n = 2, 3, 4, 5). The methodology adopted is the time-dependent coupled Hartree–Fock theory within a variational scheme, which incorporates partial correlation effects. The effect of encapsulation has been introduced through an effective potential in the one particle potential part due to the fullerene cage. Interesting pattern of the relevant properties of the confined He atom has been observed depending upon overall charge of the fullerene cage.