  The rapid Gaussian falloff of the oscillator functions at large radius makes
them poorly suited for the description of the asymptotic properties of the
nuclear wave function, a problem which becomes particularly acute for halo
nuclei. We consider an alternative basis for ab initio no-core configuration
interaction (NCCI) calculations, built from Coulomb-Sturmian radial functions,
allowing for realistic exponential falloff. NCCI calculations are carried out
for the neutron halo nuclei 6,8He, as well as the baseline case 4He, with the
JISP16 nucleon-nucleon interaction. Estimates are made for the root-mean-square
radii of the proton and matter distributions.
