The convergence of the close-coupling formalism is studied by expanding the target states in an orthogonal ${\mathit{L}}^2$ Laguerre basis. The theory is without approximation, and convergence is established by simply increasing the basis size. We present convergent elastic, 2s, and 2p differential cross sections, spin asymmetries, and angular-correlation parameters for the 2p excitation at 35, 54.4, and 100 eV. Integrated and total cross sections as well as T-matrix elements for the first five partial waves are also given.

• Received 6 April 1992

DOI:https://doi.org/10.1103/PhysRevA.46.6995