It should noted that a few features are still in development, or are currently quite rudi-mentary. Of particular importance are procedures for the automatic selection of contraction coefficients. This is somewhat harder to distill as a list of instructions, relying on a certain amount of 'chemical intuition', insofar as that exists. One traditional approach is to construct general contractions by considering the density matrix coefficients in an atomic calculation. It is not clear, however, how this would generalise to, for example, the Molec-ularBasis mentioned earlier.