How will the dichlophenyl group affect the geometric structure, electronic properties, and static linear polarizability of La@C72?

The generally gradient approximation based on density functional theory is used to find out what effects are brought by the dichlophenyl group on the La@C72 molecule. It is found that the most stable isomer of La@C72 is formed by placing the La atom into the C2 symmetric C72 cage. The most favorable endohedral site of La atom in La@C72(C2) is off-center along the C2 axis in the σh plane pointing to the [5, 5] bond, the fusion of two pentagons, yielding a structure marked as La@C72(C2)-1. It is interesting that five La@C72(C2) isomers considered all have 1μB magnetic moment, while La@C72(C6H3Cl2) has a closed-shell electronic structure. With respect to the static linear polarizability, La@C72(C2)-1 shows a giant anisotropy than that of C60 because of its lower C2 symmetric structure in contrast to the isotropic polarizability of C60 with Ih symmetric structure, as well as the transference of three valence electrons from La atom to the carbon cage. However, the three components of La@C72(C6H3Cl2) along the x, y, and z directions are 638.53, 228.86, and 413.22 Å3 with the mean value 426.87 Å3, much larger than those of 77.4 Å3 for C60 and 363.47 Å3 for La@C72(C2)-1. The static linear polarizabily anisotropy of La@C72(C6H3Cl2), 355.26 Å3, is much larger than that of La@C72(C2)-1, 129.18 Å3, because the inclined dichlorophenyl group completely destroys the C2 symmetry of La@C72(C2)-1.