title: Detailed interpretation of the 5f-6d absorption spectrum of U3+ in Cs2NaYCl6 and high pressure effects based on an ab initio simulation.
abstract: The 5f-->6d(t(2g)) absorption spectrum of U(3+)-doped Cs(2)NaYCl(6) is simulated with a quantum chemical ab initio embedded-cluster approach applied to U(3+) substitutional defects of O(h) local symmetry. The first-principles results help to provide a detailed interpretation of the very rich experimental absorption spectrum of this material between 14 000 and 25 000 cm(-1). Also, the effects of high pressures up to 26 kbars on the absorption spectrum are predicted, the most relevant feature being a redshift of around 21 cm(-1)/kbar, which is the fingerprint of a bond length shortening upon 5f-->6d(t(2g)) excitation.
authors.affiliation: Departamento de Química, C-XIV, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Ruipérez
authors.forename: Zoila
authors.initials: Z
authors.lastname: Barandiarán
authors.forename: Luis
authors.initials: L
authors.lastname: Seijo