caa a22 4500 445868325 CHVBK 20180317145504.0 cr unu---uuuuu 170323e20110101xx s 000 0 eng 10.1140/epjd/e2010-10500-9 doi (NATIONALLICENCE)springer-10.1140/epjd/e2010-10500-9 On highly accurate calculations of the excited n1S(L [Elektronische Daten] 0)-states in helium atoms [A. M. Frolov, D. M. Wardlaw] Abstract.: The total energies and various bound state properties of the excited 21S(L = 0)-states in two-electron helium atoms, including the $^{\infty}\rm He$, $^4\rm He$ and $^3\rm He$ atoms, are determined to very high numerical accuracy. The convergence of the results obtained for some electron-nuclear and electron-electron expectation values and, in particular, for the electron-nuclear and electron-electron cusp values, is discussed. The field component of the isotope shift and lowest order QED correction are estimated for the 21S(L = 0)-states in the 4He and 3He atoms. We also apply our highly accurate methods to numerical computations of the excited n 1S-states (for n = 3 and 4) in two-electron atomic systems. EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg, 2011 Frolov A. M. Department of Chemistry, University of Western Ontario, N6A 5B7 London, Ontario, Canada aut Wardlaw D. M. Department of Chemistry, University of Western Ontario, N6A 5B7 London, Ontario, Canada aut The European Physical Journal D Springer-Verlag 61/2(2011-01-01), 305-313 1434-6060 61:2<305 2011 61 10053 https://doi.org/10.1140/epjd/e2010-10500-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1140/epjd/e2010-10500-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Frolov A. M. Department of Chemistry, University of Western Ontario, N6A 5B7 London, Ontario, Canada aut NATIONALLICENCE 700 1- Wardlaw D. M. Department of Chemistry, University of Western Ontario, N6A 5B7 London, Ontario, Canada aut NATIONALLICENCE 773 0- The European Physical Journal D Springer-Verlag 61/2(2011-01-01), 305-313 1434-6060 61:2<305 2011 61 10053 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer