Sturmian label

First, we try the Sturmian method outUned in Section 6.2.1. The computations are performed in a basis of 50 Sturmian states as defined in (6.2.3) for three different choices of the Sturmian label, a = 3,4,5. The resulting ionization probabiUties after 100 cycles of the field, P (IOO), are shown in Figs. 6.8(a) - (c) for the three different Stm-mian labels, respectively. Our first impression is that the results depend strongly on the choice of the Sturmian label. This dependence can in principle be reduced, but only at the cost of increasing the basis size substantially. 

Fig. 6.8. Ionization rates computed with the Sturmian method for three different Sturmian labels, (a) a = 3, (b) a = 4, (c) a = 5.

We have dropped the index i because for the moment we are dealing with a single electron). The use of Coulomb Sturmian basis functions located on the different atoms of a molecule to solve (63) was pioneered by C.E. Wulfman, B. Judd, T. Koga, V. Aquilanti, and others [30-37]. These authors solved the Schrodinger equation in momentum space, but here we will use a direct-space treatment to reach the same results. Our basis functions will be labeled by the set of indices... 

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