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The hyperspherical expansion in the He atom problem is studied. The methods used permit a great number of basis hyperspherical harmonics to be retained in a simple way. The EB value obtained for Kmax=40 is 2.9018 au. The extrapolation to Kmax= infinity gives EB=2.9038 au. A new basis is proposed having technical advantages similar to those of HH but which ensure a faster convergence.
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Efros et al. (1982) studied this question.
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