Sie befinden Sich nicht im Netzwerk der Universität Paderborn. Der Zugriff auf elektronische Ressourcen ist gegebenenfalls nur via VPN oder Shibboleth (DFN-AAI) möglich. mehr Informationen...
Confined helium: Excited singlet and triplet states
Ist Teil von
Physics letters. A, 2013-11, Vol.377 (40), p.2880-2883
Ort / Verlag
Elsevier B.V
Erscheinungsjahr
2013
Link zum Volltext
Quelle
Alma/SFX Local Collection
Beschreibungen/Notizen
Energies for the first four singlet and triplet S states of a helium atom confined at the center of an impenetrable sphere are reported. All calculations used explicitly correlated Hylleraas basis sets. The first triplet state is shown to lie below the first excited singlet state only when the confinement radius is greater than 0.988a0. A simple configuration interaction calculation was performed in parallel with Hylleraas calculation. The one-electron atomic orbitals of the configuration treatment provide insight into the physical concepts behind the numerical results of the Hylleraas treatment. This was particularly helpful in understanding the level crossing and avoided crossings observed with changing confinement radius.
•Energies are calculated for singlet and triplet S states of the confined helium atom.•Level crossings and avoided crossings occur as the confinement radius changes.•When the confinement radius is less than 0.988a0, the lowest singlet and triplet excited states cross.