  The article presents calculated dissociative recombination (DR) rate
coefficients for H+3 . The previous theoretical work on H+3 was performed using
the adiabatic hyperspherical approximation to calculate the target ion
vibrational states and it considered just a limited number of ionic rotational
states. In this study, we use accurate vibrational wave functions and a larger
number of possible rotational states of the H3+ ground vibrational level. The
DR rate coefficient obtained is found to agree better with the experimental
data from storage-ring experiments than the previous theoretical calculation.
We present evidence that excited rotational states could be playing an
important role in those experiments for collision energies above 10 meV. The DR
rate coefficients calculated separately for ortho- and para-H3+ are predicted
to differ significantly at low energy, a result consistent with a recent
experiment. We also present DR rate coefficients for vibrationally-excited
initial states of H3+, which are found to be somewhat larger than the rate
coefficient for the ground vibrational level.

Atomic Physics