Effect of different subsets on convergence patterns of hyperspherical harmonic expansion for the S states of the helium atom

✍ Scribed by Yi-Xuan Wang; Yu-Xiang Bu; Cong-Hao Deng

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 150 KB
• Volume: 64
• Category: Article
• ISSN: 0020-7608
• DOI: 10.1002/(sici)1097-461x(1997)64:6<661::aid-qua3>3.0.co;2-u

✦ Synopsis

Effects of different subsets on convergence patterns of hyperspherical

Ž .

1 3 harmonic HH expansions for the low-lying S and S states of the helium atom have been investigated with the correlation-function-hyperspherical-harmonic-generalized-Ž . Laguerre-function CFHHGLF method by successively introducing HH subsets with the Ž . fixed three-dimensional angular momentums l into the atomic wave functions. The eigenenergies given by the HH subsets of l s 0, 1, 2, and 3 are in good agreement with Ž . the best s-, sp-, spd-, and spdf limits of variational configuration interaction CI calculations, respectively. The final eigenenergies of the ground state as well as the examined low-lying excited 1 S and 3 S states are quite close to the exact Hylleraas CI Ž . HCI values at the sixth decimal place. Moreover, l s 0 and l / 0 expansion results also tell us that it is not necessary to take into account too many HHs at the given l, especially for higher l, and that the more the absolute electron correlation energies the bigger l it takes to obtain precise eigenenergies.