Helium n^{1,3}S excited states obtained with an angular correlated configuration interaction method

K.V. RODRIGUEZ, V.Y. GONZALEZ, L.U. ANCARANI, D.M. MITNIK, AND G. GASANEO

Graz, Austria

Conferencia; 40th European Group for Atomic Systems (EGAS) conference; 2008

EGAS

We construct approximate helium wavefunctions for ground and excited nS states through the angular correlated configuration interaction (ACCI) method. The functions satisfy exactly all two-body Kato cusp conditions. The trial wavefunction involves then N linear variational parameters which are obtained by solving a generalized eigenvalue problem. The n1;3S states obtained in this way form an orthogonal set of wavefunctions. Quite accurate energies values for both the ground and excited states can be obtained with only a relatively low number of terms.