Study of non-orthogonal Laguerre-L$\mathsf{^{2}}$ method for helium atom

We present a technique for describing solutions of the helium atom by using the non-orthogonal Laguerre-L² basis functions. The frozen-core approximation is used to calculate the helium energies. The completeness of helium wavefunctions obtained is studied in terms of weights of the Gaussian quadrature. The convergence of the energies is shown as the L² basis size increases and the completeness of the L² wave functions is also shown for different basis size.Received: 20 August 2003, Published online: 6 January 2004PACS: 34.80.Bm Elastic scattering of electrons by atoms and molecules - 34.80.Dp Atomic excitation and ionization by electron impact