title: Encapsulation of an f-block metal atom/ion to enhance the stability of C20 with the I(h) symmetry.
abstract: Based on the density functional theory, the geometric and electronic structures, chemical stability, and bonding properties of the endohedral metallofullerenes, M@C20 (M = Eu(3-), Am(3-), Gd(2-), Cm(2-), Tb(-), Bk(-), Dy, Cf, Ho(+), Es(+), Er(2+), Fm(2+), Tm(3+), Md(3+), Yb(4+), No(4+), Lu(5+), and Lr(5+)), were investigated. Through encapsulation of an f-block metal atom/ion with 12 valence electrons, the bare C20 cage with the D2h point group could be stabilized to a highly symmetrical Ih structure. The calculated values of HOMO-LUMO energy gaps using the B3lYP and BHHLYP functionals ranged from 2.22 to 5.39 eV and from 3.89 to 7.95 eV, respectively. The stability of these metal-encapsulated clusters can be attributed to the 32-electron rule, where the central metal atom's orbitals strongly participated in the t2u, gu, t1u, hg, and ag valence molecular orbitals.
authors.affiliation: Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, P. R. China. zwzhou@at-c.net.
authors.forename: Fanchen
authors.initials: F
authors.lastname: Meng
authors.forename: Zuowan
authors.initials: Z
authors.lastname: Zhou
authors.forename: Pinliang
authors.initials: P
authors.lastname: Zhang
authors.forename: Man
authors.initials: M
authors.lastname: Jiang
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Xu
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.forename: Jihua
authors.initials: J
authors.lastname: Gou
authors.forename: David
authors.initials: D
authors.lastname: Hui
authors.forename: Dong
authors.initials: D
authors.lastname: Die