of the integrator below 0.1 to 0.2 Bohr, in order to properly follow the details of the radial coefficients. Other propagation parameters were taken as the <span style="font-variant:small-caps;">molscat</span> default values.

[ccc]{}\
$E_{\rm tot}\:\rm (cm^{-1})$ & Energy step ($\rm cm^{-1}$) & Method\
$0.3 \rightarrow 60$ & $0.1$ & CC\
$60 \rightarrow 110$ & $10$ & CC\
$40 \rightarrow 200$ & $10$ & CS\
$50 \rightarrow 800$ & $10-100 $ & IOS\
\
$0\rightarrow 30 $& $1$ & CC\
\
$0\rightarrow 25 $& $0.1$ & CC\
$25\rightarrow 100 $& $5$ & CC\
$100\rightarrow 150 $& $10$ & CC\

Two examples of deexcitation cross-sections are shown in figure \[fig:sectionop\]. We see that for energies between threshold and about 20 cm$^{-1}$ above threshold, the cross-section displays many shape resonances, justifying *a posteriori* our very fine energy grid. This behaviour is by no means unexpected and is very similar to most earlier calculations is many different systems, see e.g. @dubernet02 [@wernli06] for a discussion. In a semi-classical point of view, those shape resonances manifest the trapping of the wave-packet between the inner repulsive wall and the outer centrifugal barrier, see @wie03 [@abrol01]. At energies higher than about 20 cm$^{-1}$ above threshold, all cross-sections become smooth 