title: Does the 4f-shell contribute to bonding in tetravalent lanthanide halides?
abstract: Lanthanide tetrahalide molecules LnX4 (Ln = Ce, Pr, Tb; X = F, Cl, Br, I) have been investigated by density functional theory at the levels of the relativistic Zero Order Regular Approximation and the relativistic energy-consistent pseudopotentials, using frozen small- and medium-cores. The calculated bond lengths and vibrational frequencies are close to the experimental data. Our calculations indicate 4f shell contributions to bonding in LnX4, in particular for the early lanthanides, which show significant overlap between the Ln 4f-shell and the halogen np-shells. The 4f shells contribute to Ln-X bonding in LnX4 about one third more than in LnX3.
authors.affiliation: School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 200240 Shanghai, China.
authors.forename: Wen-Xin
authors.initials: WX
authors.lastname: Ji
authors.affiliation: School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 200240 Shanghai, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.affiliation: School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 200240 Shanghai, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 200240 Shanghai, China.
authors.forename: Shu-Guang
authors.initials: SG
authors.lastname: Wang