A new systematic procedure for constructing potential curves for diatomic molecules is developed. The procedure is similar to the well-known Dunham method, except that the expansion parameter is (R-Re)/R instead of (R-Re)/Re. The new expansion, which has a formal theoretical basis, is shown to be superior in terms of both rate of convergence and region of convergence. It is shown how the expansion coefficients may be obtained from spectroscopic data, and the proper behavior of the potential at large R is shown to allow one to determine additional coefficients and to determine dissociation energies. To illustrate the method, the ground states of hydrogen flouride and carbon monoxide are treated. Possible extensions to polyatomic molecules are briefly discussed.

The process of documenting and describing the world's languages is undergoing radical transformation with the rapid uptake of new digital technologies for capture, storage, annotation and dissemination. However, uncritical adoption of new tools and technologies is leading to resources that are difficult to reuse and which are less portable than the conventional printed resources they replace. We begin by reviewing current uses of software tools and digital technologies for language documentation and description. This sheds light on how digital language documentation and description are created and managed, leading to an analysis of seven portability problems under the following headings: content, format, discovery, access, citation, preservation and rights. After characterizing each problem we provide a series of value statements, and this provides the framework for a broad range of best practice recommendations.

The use of model potentials in pseudopotential calculations is discussed, and a set of desirable criteria for model potentials is suggested. The Hellmann potential and the Abarenkov and Heine potential are examined, and it is shown that both potentials are useful, but neither fully satisfies the suggested desiderata. A new potential of the form, V(r) =-Z!r+"1:,IBIPI!r 2 , where PI is the projection operator over the subspace of spherical harmonics of a given I, is proposed. A physical interpretation of the potential in terms of a "Pauli force" and a polarized core is given. Ionization energies for excited S, P, D, and F states for onevalence-electron atoms are calculated. The new potential is also applied to two-valence-electron atoms, and their calculated valence-state energies are shown to be in good agreement with experimental values.

A new procedure for generating approximate valence and Rydberg orbitals is proposed. The method involves the analytic determination of the eigenfunctions of a model Hamiltonian and leads to orbitals which are functions of quantum numbers and quantum defects. The new functions are shown to be similar to previously obtained orbitals and are used to derive a general formula for transition integrals. Illustrative results for Li and Be+ are excellent; results for Na, K, and Mg are satisfactory.