Precision calculation of energy levels for four-valent Si I*
1 Petersburg Nuclear Physics Institute, 1, Orlova roscha mcr., Gatchina, Leningrad region, 188300, Russia
2 St. Petersburg Electrotechnical University “LETI”, Prof. Popov Str. 5, St. Petersburg 197376, Russia
Received: 15 November 2016
Received in final form: 12 February 2017
Published online: 23 May 2017
We report the results of our calculation of low-lying levels of neutral Si using a combination of the configuration interaction and many-body perturbation theory (CI+MBPT method). We treat Si I as an atom with four valence electrons, and use two different starting approximations, namely VN−2 and VN−4. We conclude that both approximations provide comparable accuracy, on the level of 1%.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2017