The density functional calculations on the structural stability, electronic properties, and static linear polarizability of the endohedral metallofullerene Ba@C74

The generalized gradient approximation based on density functional theory is applied to study the structural stability, electronic properties, and static linear polarizability of Ba@C74. It is found that the most favorable endohedral site for a Ba atom is off-center under a [6, 6] double bond along the C2 axis on the σh plane, which is denoted as Ba@C74-2. This result can be explained by the electrostatic potential map of the C742- on the σh plane. Of particular interest is the static linear polarizability of Ba@C74-2. The calculated polarizability component αzz of Ba@C74-2 687.3 Å3 is nine times that of C60 77.4 Å3, while αxx and αyy are zero. This large anisotropy may be due to its lower C2v symmetry compared to C60 with Ih-symmetry, as well as the transference of about two valence electrons from the Ba atom to the carbon cage.