He- D-2 weakly bound triply excited resonances: Interpretation of previously unexplained structures in the experimental spectrum

Piangos, NA; Komninos, Y; Nicolaides, CA

dc.contributor.author	Piangos, NA	en
dc.contributor.author	Komninos, Y	en
dc.contributor.author	Nicolaides, CA	en
dc.date.accessioned	2014-03-01T01:52:05Z
dc.date.available	2014-03-01T01:52:05Z
dc.date.issued	2002	en
dc.identifier.issn	1050-2947	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/26558
dc.subject.classification	Optics	en
dc.subject.classification	Physics, Atomic, Molecular & Chemical	en
dc.subject.other	ELECTRONIC-STRUCTURE	en
dc.subject.other	STATES	en
dc.subject.other	COMPUTATION	en
dc.subject.other	WIDTHS	en
dc.subject.other	HELIUM	en
dc.title	He- D-2 weakly bound triply excited resonances: Interpretation of previously unexplained structures in the experimental spectrum	en
heal.type	journalArticle	en
heal.identifier.secondary	032721	en
heal.language	English	en
heal.publicationDate	2002	en
heal.abstract	A He plus electron scattering experiment by Gosselin and Marmet [Phys. Rev. A 41, 1335 (1990)] produced the previously known He- 2s2p(2) D-2 resonance at 58.283+/-0.003 eV with a width Gamma=59+/-4 meV, and two new structures at 58.415+/-0.005 and 58.48+/-0.02 eV with Gamma<2 meV and Gamma=70+/-20 meV, respectively. The nature of these last two structures has since remained unexplained. Heuristic analysis of the spectrum of the triply excited states (TES) of He- and of conditions of electron correlation and possible localization, and application of the state-specific theory (SST) for the calculation of electronic structures and properties led to the determination of three resonance states of D-2 symmetry that explain quantitatively the experimental data. The implementation of the SST involved the combination of suitable choices of optimized orbitals, of nonorthonormal configuration interaction, and of mixing of bound with scattering configurations. The first two D-2 TES contain the 2s2p(2) configuration as a major component, but strong radial correlation results in the spatial separation of the two p spin orbitals. The third TES, computed systematically with up to 996 optimized configurations, is an open-channel like localized wave packet.	en
heal.publisher	AMERICAN PHYSICAL SOC	en
heal.journalName	PHYSICAL REVIEW A	en
dc.identifier.isi	ISI:000178382500080	en
dc.identifier.volume	66	en
dc.identifier.issue	3	en