Comment on 'Formation of H(2p) and H(2s) in collisions of He⁺with H atoms'

A striking discrepancy between calculated (Errea et al., 1989) and measured (Geddes et al., 1994) partial excitation cross sections in He + +H collisions poses the problem of the predictive value of molecular calculations. We indicate the cause of the discrepancy, and discuss the general issue.