Approximate wavefunctions for H2+ of the James and LCAO types are discussed in terms of their ability to serve as useful representations of the exact function. For a wavefunction to be suitable for this, we require that, in addition to giving a good energy, (a) it have a large overlap with the exact wavefunction, and (b) values obtained by variation for parameters in the approximation functions be the values required to maximize the overlap. With three-parameter functions, the overlap is essentially complete. The accuracy to which values of parameters can be predicted is only approximate, which may lead to difficulty when these are to be used to help understand the process of molecular binding.