Radiative decay from doubly to singly excited states of He via generalization of Laguerre-type orbitals: A non-orthogonal formalism

• 来源期刊: 中国物理（英文版）
• 关键词: doubly excited states singly excited states analytic basis functions non-orthogonality formalism
• 年，卷（期）: 2007,（2）
• 页码范围: 374-381
• 页数: 8页
• 语种: 英文

摘要

By taking full account of the non-orthogonality of the orbitals between the low-lying doubly excited states 1po and the singly excited states 1Se and 1 De of He, the corresponding radiative decay rates have been investigated theoretically via analytic generalized Laguerre-type atomic orbitals at a nearly numerical multi-configuration self-consistent field accuracy in a general non-orthogonal configuration interaction scheme. From these rates, we calculate the VUV photon emission and metastable atom spectra, and both are found to be in good qualitative agreement with recent excellent measurements. We obtain, successfully, the enhancement of the VUV photon spectrum, experimentally observed at the energy of (2s4p-4s2p)/(2p,3d) 1p° as compared with other nearby lying states. The mechanism proposed by Odling-Smee et al is verified, implying that taking appropriate account of the overlap existing between orbitals of the low-lying doubly excited and singly excited states (especially important for the compact orbitals) can reveal basic physical dominant mechanism and is crucial in understanding these spectra.