2008/09/22 by N. C. Bacalis, Naoum C. Bacalis, Bacalis, Naoum C.
Engineering · Physics and Astronomy · #Atomic Physics (physics.atom-ph) #Chemical Physics (physics.chem-ph) #Computational Physics (physics.comp-ph) #FOS: Physical sciences #Photonic and Optical Devices #physics.atom-ph #physics.chem-ph #physics.comp-ph
paper · pdf · doi:10.48550/arxiv.0809.3826
4 pages, 1 figure
arxiv created 2008/09/22 · openalex publication_date 2008/09/22 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
For the computation of excited states, the standard solutions of the Schroedinger equation, using higher roots of a secular equation in a finite N-dimensional function space, by the Hylleraas-Undheim and MacDonald theorem, have several restrictions, which render them of lower quality, relative to the lowest root, if the latter is good enough. These deficiencies are reported, that prevent from comparisons with accurate experiments.