INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, vol.76, no.5, pp.618-625, 2000 (SCI-Expanded)
In this article exact solutions of a two-electron Schrodinger equation for the Coulomb potential were extended to the Fues-Kratzer-type potential: ((Z) over cap(Omega)/r) + ((A) over cap/r(2)). The wave function psi(r, Omega) is expanded into generalized Laguerre polynomials and hyperspherical harmonics. An analytical expression of two-electron systems is given for matrix elements and accurate energy eigenvalues of the excited state of S-1,S-3 helium are calculated by using the hyperspherical harmonics method. The present results are compared with previous theoretical calculations and it is concluded that the convergence of energy eigenvalues is faster. (C) 2000 John Wiley & Sons, Inc.