Cross section for the radiative association of He<sup>+</sup> (1s) and H(1s) towards the fundamental <em>X</em> <sup>1</sup>Σ<sup>+</sup> state via the <em>A</em> <sup>1</sup>Σ<sup>+</sup> channel, with (black full line) and without (black dotted line) taking its vibrational dependence into account

<p><strong>Figure 6.</strong> Cross section for the radiative association of He<sup>+</sup> (1s) and H(1s) towards the fundamental <em>X</em> <sup>1</sup>Σ<sup>+</sup> state via the <em>A</em> <sup>1</sup>Σ<sup>+</sup> channel, with (black full line) and without (black dotted line) taking its vibrational dependence into account. The results are compared with those of Kraemer <em>et al</em> (<a href="http://iopscience.iop.org/0953-4075/46/15/155201/article#jpb460442bib20" target="_blank">1995</a>) (red dashed line).</p> <p><strong>Abstract</strong></p> <p>We illustrate some of the difficulties that may be encountered when computing photodissociation and radiative association cross sections from the same time-dependent approach based on wavepacket propagation. The total and partial photodissociation cross sections from the 33 vibrational levels of the <em>b</em> <sup>3</sup>Σ<sup>+</sup> state of HeH<sup>+</sup> towards the nine other <sup>3</sup>Σ<sup>+</sup> and 6 <sup>3</sup>Π <em>n</em> = 2, 3 higher lying electronic states are calculated, using the autocorrelation method introduced by Heller (1978 <em>J. Chem. Phys.</em> <strong>68</strong> 3891) and the method based on the asymptotic behaviour of wavepackets introduced by Balint-Kurti <em>et al</em> (1990 <em>J. Chem. Soc. Faraday Trans.</em> <strong>86</strong> 1741). The corresponding radiative association cross sections are extracted from the same calculations, and the photodissociation and radiative association rate constants are determined.</p>