Role of initial orbital alignment in H++K(4p) collisions at low energies

We report calculations of state-selective electron capture by H+ from K(4p) in Sigma and Pi alignments, in the 0.01-1 keV/amu energy range. We use, in the impact parameter formalism, the semiclassical close-coupling method wi th molecular-state expansion embodying electronic translation factors. Mole cular states and adiabatic states are obtained from standard one-electron L CAO calculations using Slater-type orbitals and pseudopotentials for the e( -)-K core interactions. In addition to the state-selective capture cross se ctions, we also have calculated the K(5s), K(3d), and K(5p) excitation cros s sections. We report the anisotropy parameters A(n) for n = 2 and n = 3 st ates of the formed H atom as well as A(ex) for populating the excited state s of the K atom for the first time. (C) 2001 John Wiley & Sons, Inc.