title: Theoretical study of the electronic spectra of neutral and cationic NpO and NpO2.
abstract: The electronic spectra of neutral NpO and NpO2 as well as of their mono- (NpO(+), NpO2(+)) and dications (NpO(2+), NpO2(2+)) were studied using multiconfigurational relativistic quantum chemical calculations at the complete active space self-consistent field/CASPT2 level of theory taking into account spin-orbit coupling. The active space included 16 orbitals: all the 7s, 6d, and 5f orbitals of neptunium together with selected orbitals of oxygen. The vertical excitation energies on the ground state geometries have been computed up to ca. 35,000 cm(-1). The gas-phase electronic spectra were evaluated on the basis of the computed Einstein coefficients at 298 K and 3000 K. The computed vertical transition energies show good agreement with previous condensed-phase results on NpO2(+) and NpO2(2+).
authors: European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe, Germany.
authors: Attila
authors: A
authors: Kovács
authors: Department of Theoretical Chemistry, Faculty of Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands.
authors: Ivan
authors: I
authors: Infante