S. Xia et Jc. Krupa, Calculated variation trends across the actinide dioxide series: electronicstructure and charge transfer transitions, J ALLOY COM, 307, 2000, pp. 61-69
Variation trends across the AnO(2) series of An5f-electron covalent bonding
and An5f-->O3s, O2p-->An5f charge transfer energies, are studied using DV-
X alpha relativistic spin-polarised computation of electronic structures ap
plied to 11 'AnO(8)' clusters, from ThO8 to FmO8. It is found that the bind
ing energies of 5f orbitals, therefore the An5f-O2p hybridisation, are incr
easing though the 5f orbitals are localising across the An series. In our c
alculations, the 3s and 3p ionic-like orbitals of O2- ions are included for
the first time as LCAO-MO bases. Then, the conduction band is a mixing of
O3s and An6d and its lower edge corresponds to an O3s-dominated state. More
over, the calculated charge transfer (CT) energies of An5f-->O3s and O2p-->
An5f transitions show the so-called tetrad effect when CT energies, respect
ively increasing and decreasing across the AnO(2) series. It is pointed out
that the tetrad effect here comes mainly from the special spin-polarised p
attern of 5f levels and the increasing general trend of 5f binding energies
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